# Rak811 Tracker Board

**URL:** <https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006>\
**Category:** End Devices (Nodes)\
**Created:** [December 7, 2017, 1:39am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006 "2017-12-07T01:39:45Z")\
**Posts on this page:** 20\
**Page:** 12

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**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 24, 2018, 11:57am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/231 "2018-04-24T11:57:09Z")

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I don’t see PA15 referenced anywhere in the source or in this forum, apart from your post. Have you thoughts about how to turn the GPS on and off? Probably on a schedule, set as part of the configuration that includes commissioning. It would probably be better if there was a power saving mode, because in my experience, a GPS that is doing a warm start (because it’s kept the latest ephemeris) can get a sync in about one second. If you turn its power off, it has to re-acquire the ephemeris, which can take 90 seconds.

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**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 24, 2018, 1:31pm UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/232 "2018-04-24T13:31:48Z")

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It has a power save mode.

> **[MAX-7\_DataSheet\_%28UBX-13004068%29.pdf](https://www.u-blox.com/sites/default/files/products/documents/MAX-7_DataSheet_%28UBX-13004068%29.pdf?utm_source=en%2Fimages%2Fdownloads%2FProduct_Docs%2FMAX-7_DataSheet_%28GPS.G7-HW-12012%29.pdf)**
>
> 1644.10 KB

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<div class="post-metadata">

**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 24, 2018, 1:45pm UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/233 "2018-04-24T13:45:47Z")

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It’s PA\_15, Russell. And it is referenced and used by GpsStart and GpsStop, but GpsStop is only called in the ComplianceTest code. So there’s no inherent GPS power saving by the tracker.

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**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 24, 2018, 2:13pm UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/234 "2018-04-24T14:13:33Z")

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Hmmm… the CPU has EEPROM. Better place to store the commissioning data than in the source code.  
After doing that, the next step is to include the source code for all regions, so that the region becomes a run-time setting rather than a compilation option.

With those two changes to the code, the only people who would need to recompile it are people who want to change the source. It’s most important to put the commissioning into EEPROM, because then you can create a set of binaries, one for each region. Then, the mundanes can just reflash with their region, which is a LOT easier.

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**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 24, 2018, 2:44pm UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/235 "2018-04-24T14:44:25Z")

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Urgh. Attempting to read from fd0 (aka stdin) using getline or read fails. I get a -1 error code from read’ing. Anybody ever used this system to read characters from the USB port?

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**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 24, 2018, 2:45pm UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/236 "2018-04-24T14:45:14Z")

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You can program power save mode using their proprietary protocol: [https://www.u-blox.com/sites/default/files/products/documents/u-blox7-V14\_ReceiverDescrProtSpec\_(GPS.G7-SW-12001)\_Public.pdf](https://www.u-blox.com/sites/default/files/products/documents/u-blox7-V14_ReceiverDescrProtSpec_%28GPS.G7-SW-12001%29_Public.pdf)

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**Author:** ![OlofAst](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/olofast/32/25844_2.png) [@OlofAst](https://www.thethingsnetwork.org/forum/u/OlofAst)\
**Post date:** [April 24, 2018, 3:38pm UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/237 "2018-04-24T15:38:28Z")

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OK. So you added a hdop byte in the data format and one has to add the decoder manualy to the things network application. I will test this.

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**Author:** ![ECE\_306](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/e/b9bd4f/32.png) [@ECE\_306](https://www.thethingsnetwork.org/forum/u/ECE_306)\
**Post date:** [April 25, 2018, 12:26am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/238 "2018-04-25T00:26:16Z")

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Hey I have been following your comments. I am having a problem connecting my device to ttn. I have changed the EUIs and application keys. I have also changed the frequency in platformio.ini to US915 as you suggested. Unfortunately all I get is this:  
OTAA:  
Dev\_EUI: xxx…  
AppEui: xxx…  
AppKey: xxx…  
OTAA Join Start…

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<div class="post-metadata">

**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 25, 2018, 1:24am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/239 "2018-04-25T01:24:12Z")

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Are you using my version of the code? Because you also need to change the LORAWAN\_DEFAULT\_DATARATE to DR\_4. My code does that when you change the region to US915. Without that, no go. Also, my code tells you the return value from SendFrame, so that if you’re not getting 0, you can track down the error you’re getting.

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<div class="post-metadata">

**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 25, 2018, 1:26am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/240 "2018-04-25T01:26:02Z")

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Yes. After adding the decoder (and note that I changed the data format to match @jpmeijers’s as he used in his arduino code, so the decoder.js and mapper.c must match), you must also add ttnmapper as an integration. Otherwise it won’t know to look at your GPS data.

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**Author:** ![lufti-iot](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/lufti-iot/32/12186_2.png) [@lufti-iot](https://www.thethingsnetwork.org/forum/u/lufti-iot)\
**Post date:** [April 25, 2018, 1:40am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/241 "2018-04-25T01:40:40Z")

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It reduced around 20mA.  
You can just use GpsStop() to do this. You can check that it use GpsMcuStop() as in gps-board.c

void GpsMcuStop( void )  
{  
GpioWrite( &GpsPowerEn, 0 ); // power down the GPS  
}

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<div class="post-metadata">

**Author:** ![lufti-iot](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/lufti-iot/32/12186_2.png) [@lufti-iot](https://www.thethingsnetwork.org/forum/u/lufti-iot)\
**Post date:** [April 25, 2018, 1:45am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/242 "2018-04-25T01:45:55Z")

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I’m using Ebiroll version code, you can just search GPS\_POWER\_ON\_PIN and you will find it defined for PA\_15. Yes the GPS need 90 seconds to acquire. My application only need the GPS coordinate during startup, so this can be managed.

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<div class="post-metadata">

**Author:** ![lufti-iot](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/lufti-iot/32/12186_2.png) [@lufti-iot](https://www.thethingsnetwork.org/forum/u/lufti-iot)\
**Post date:** [April 25, 2018, 1:50am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/243 "2018-04-25T01:50:38Z")

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yes I already read this. Any information for sample code sent to activate PSM via its UART?

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<div class="post-metadata">

**Author:** ![ECE\_306](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/e/b9bd4f/32.png) [@ECE\_306](https://www.thethingsnetwork.org/forum/u/ECE_306)\
**Post date:** [April 25, 2018, 3:36am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/244 "2018-04-25T03:36:07Z")

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I downloaded your gps-node-examples-master folder. Here is what I did all in atom:  
Opened gps-node-examples-master, modified Commissioning.h, added rak811.json to ststm32 boards, modified platform.ini to US915. Then ran gps-node-examples-master\RAK811-Tracker\> pio run. It returned :  
Calculating size .pioenvs\rak811\firmware.elf  
text data bss dec hex filename  
52612 1564 5956 60132 eae4 .pioenvs\rak811\firmware.elf  
===== [SUCCESS] Took 4.99 seconds=====  
 ![run](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/8/88a68c465890d15b71766d911f884053e726dedd.PNG)

In UART terminal I get:  
RAK811 BreakBoard soft version: 1.0.2  
Selected LoraWAN 1.0.2 Region: US915  
OTAA:  
Dev\_EUI: xxxx  
AppEui: xxxx  
AppKey: xxxx  
OTAA Join Start…

Where and how do I change to LORAWAN\_DEFAULT\_DATARATE to DR\_4?

I am pretty new at this and had to read a looooot just to get to where I am now. Could you give me some more detailed help please. I truly appreciate it!!!

My goal is to use the Rak811 tracking to output on the ttn mapper. I have a gateway already setup to US915.- Thank you

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<div class="post-metadata">

**Author:** ![LoRaTracker](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/loratracker/32/48502_2.png) [@LoRaTracker](https://www.thethingsnetwork.org/forum/u/LoRaTracker)\
**Post date:** [April 25, 2018, 7:41am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/245 "2018-04-25T07:41:50Z")

</div>

Indeed they do, most of the UBLOXs can be sent a command to go into low power mode and that can be used as a basis for a warm start setup. It wakes up on activity on the GPSs RX pin.

Current consumption varies depending on the model, but generally 100uA to 50uA.

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**Author:** ![jcaridadhdez](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jcaridadhdez/32/40195_2.png) [@jcaridadhdez](https://www.thethingsnetwork.org/forum/u/jcaridadhdez)\
**Post date:** [April 25, 2018, 7:45am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/246 "2018-04-25T07:45:29Z")

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I think now it is already done. You can see it in mapper.c in lines ~90 and ~95 that for US915 it is defined DR\_4.  
If your version is not updated enough, you have to delete (again in mapper.c) line 40 an add two defines in the lines I mentioned before like that  
#define LORAWAN\_DEFAULT\_DATARATE DR\_5  
Before line 93 and  
#define LORAWAN\_DEFAULT\_DATARATE DR\_4  
before line 97

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<div class="post-metadata">

**Author:** ![OlofAst](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/olofast/32/25844_2.png) [@OlofAst](https://www.thethingsnetwork.org/forum/u/OlofAst)\
**Post date:** [April 25, 2018, 9:29am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/247 "2018-04-25T09:29:58Z")

</div>

Oh OK. But I still got,  
{  
“alt”: -18311,  
“hdop”: 0,  
“lat”: -88.92324322004576,  
“lon”: -155.78059528950425  
}  
From  
018809113902B879000AF0  
Should have been something more like,  
“latitude”: 59.423046,  
“longitude”: 17.829844,

decoded.lat = ((bytes[0]\<\<16)\>\>\>0) + ((bytes[1]\<\<8)\>\>\>0) + bytes[2];  
decoded.lat = (decoded.lat / 16777215.0 \* 180) - 90;  
decoded.lon = ((bytes[3]\<\<16)\>\>\>0) + ((bytes[4]\<\<8)\>\>\>0) + bytes[5];  
decoded.lon = (decoded.lon / 16777215.0 \* 360) - 180;  
var altValue = ((bytes[6]\<\<8)\>\>\>0) + bytes[7];  
var sign = bytes[6] & (1 \<\< 7);  
if(sign) {

Hmmm…

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<div class="post-metadata">

**Author:** ![jcaridadhdez](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jcaridadhdez/32/40195_2.png) [@jcaridadhdez](https://www.thethingsnetwork.org/forum/u/jcaridadhdez)\
**Post date:** [April 25, 2018, 10:57am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/249 "2018-04-25T10:57:51Z")

</div>

I use some similar like this one: [Best practices when sending GPS location data](https://www.thethingsnetwork.org/forum/t/best-practices-when-sending-gps-location-data/1242/21)

this for the encoder:  
int32\_t lat = latitude \* 10000;  
int32\_t lon = longitude \* 10000;  
int16\_t alt = altitudeGps \* 100;  
int8\_t hdev = hdopGps \* 10;

```
    if (ret == SUCCESS) {

        AppData[0] = lat;
        AppData[1] = lat >> 8;
        AppData[2] = lat >> 16;

        AppData[3] = lon;
        AppData[4] = lon >> 8;
        AppData[5] = lon >> 16;

        AppData[6] = alt;
        AppData[7] = alt >> 8;

        AppData[8] = hdev;

        AppDataSize = 9;

```

and this for the decoder:

```
function Decoder(b, port) {
var decoded = {};
switch (port) {
    case 2:
    var lat = (b[0] | b[1]<<8 | b[2]<<16 | (b[2] & 0x80 ? 0xFF<<24 : 0)) / 10000.0;
    var lon = (b[3] | b[4]<<8 | b[5]<<16 | (b[5] & 0x80 ? 0xFF<<24 : 0)) / 10000.0;
    var alt = (b[6] | b[7]<<8 | (b[7] & 0x80 ? 0xFFFF<<16 : 0)) / 100.0;
    var hdop = b[8] / 10.0;

        decoded = {
            "location": {
                "latitude": lat,
                "longitude": lon,
                "altitude": alt,
                "hdop": hdop
            },
        };
    break;

    case 3:
    var bat = (b[0] | b[1]<<8 | (b[1] & 0x80 ? 0xFFFF<<16 : 0)) * 10.0;

    decoded ={
        "battery":{
            "bat":bat
        }
    };
    break;

    case 4:
    var aX = (b[0] | b[1]<<8 | (b[1] & 0x80 ? 0xFFFF<<16 : 0)) / 10.0;
    var aY = (b[2] | b[3]<<8 | (b[3] & 0x80 ? 0xFFFF<<16 : 0)) / 10.0;
    var aZ = (b[4] | b[5]<<8 | (b[5] & 0x80 ? 0xFFFF<<16 : 0)) / 10.0;

    decoded ={
        "acceleration":{
            "aX":aX,
            "aY":aY,
            "aZ":aZ,
        }
    };
    break;
}
return decoded;

}

```

Tested in Salamanca (where I have negative longitude) and Budapest (all positive) and good results

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<div class="post-metadata">

**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 25, 2018, 11:56am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/250 "2018-04-25T11:56:19Z")

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That’s going to run out of bits to hold any altitude greater than 327.67 meters. No need to multiply the altitude by 100.

While there’s nothing (else) wrong with your data format, I think it’s preferable to stick to the precedent set by @jpmeijers’es Arduino data format.

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<div class="post-metadata">

**Author:** ![RussNelson](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/russnelson/32/44142_2.png) [@RussNelson](https://www.thethingsnetwork.org/forum/u/RussNelson)\
**Post date:** [April 25, 2018, 11:58am UTC](https://www.thethingsnetwork.org/forum/t/rak811-tracker-board/11006/251 "2018-04-25T11:58:40Z")

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My code already sets DR\_4 when in US915 and DR\_5 when in EU868, so that’s not the problem. I don’t know why you’re having trouble with joining. You’re not doing anything wrong that I can see, and you haven’t made any mistakes I made. Double-check your credentials – if they’re wrong, a join will never work.

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