[PCB] Pro mini / RFM95W / 18650 solar chargeable

I recieved fine PCB from @Wijnand.


Pictures follows.


Hi @All

So i know @Wijnand would share his PCBs. He let us know: What's your experience with pcbs.io?

Something goes wrong with his account. I don`t know how to help. New owner of pcbs.io is https://www.makerbright.com/ ?

Is that the solution to get in contact to solve the problem?


I uploaded the design to pcbs.io again and that works.


Hey @Wijnand cool! :slight_smile:

Are you sharing? And show a link to the PCB?


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For better use of the battery it could be used the MCP1700-300 (3 V output) or MCP1700-280 (2.8V output) to take into account the dropout voltage.
MCP1700 typical dropout voltage is 178 mV and maximum 350 mV at 25°C and load 250 mA.

Hello Mario

Great work!

One thing: I always try to avoid the linked battery holder in your blog, this spring version is very bad, maybe this is not a real issue at those low power applications, but the contact between the springs and the battery is very poor. I therefore always use some massive battery holders, like this one: https://www.aliexpress.com/item//32691749341.html

Where can we order the boards?
If you could share the files for the 3D case would be great! I could also print some if someone from Switzerland is interested in the case and doesn’t have a printer.

Thank you!

Hello my friend!
Theoretically, I can share the plans, but I’m currently working on version 2. This will be completely open hardware and so I can upload them on various platforms.
I hope you have a little patience;)

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Is there anyone with experience with the CC1310? My new design (a VT-s02c module from Vincent Tang/China equipped with a CC1310 from Texas Instruments) is the next step to go to an IoT node supporting services for 10 years with a CR2032 coin cell battery (see for the concept: http://www.ti.com/tool/TIDA-00484). You can find the PCB at https://PCBs.io/share/rG9GP. Not tested yet!!!

Do those modules support LoRa modulation? The only references I found mention it supporting a modulation similar to LoRa.

First (after I recieved the PCB’s) I am going to test the power concept of TI. Next step to test the HF. I just read “no LoRa support”, see: http://e2e.ti.com/support/wireless_connectivity/proprietary_sub_1_ghz_simpliciti/f/156/t/611585

Not specifically, but it looks like its a FSK type device which needs signal levels around 5dB to 10dB above noise level to operate, wheras LoRa devices can operate at up to 20dB below noise level, a significant link margin improvement.

The LoRa devices go down to circa 0.2uA in sleep mode so why would you want to use something else ?

If you want to order my design from pcbs.io, maybe you have to wait a few days because there will be an update soon. Improved the antenna connection (@marioz) and ADC6 and ADC7 (analog exclusivily) are not connected to JP3 anymore but PB0 and PB1 (possibility for soft serial).

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hi Wijnand
when do you update? There is still the “old” version on PCBs.io

At.this moment I am in Italie (F1, Monza, Max Verstappen) until friday. I will try to update it the next weekend. Regards…


OK, the update is there (https://PCBs.io/share/46aR0). The update to V2.0: ADC6 and ADC7 (analog exclusivily) are not connected to JP3 anymore but PB0 and PB1 (possibility for soft serial). The HF part has now a switch to SMA or spring antenna and added are GND planes on both sides. If there is interrest I can add an i2c sensor (temp and/or humidity) above JP3. Let me know…


The PCB design with the VT-s02c module from Vincent Tang/China equipped with a CC1310 from Texas Instruments is also updated to V2.0 and tested for basic functions with Code Composer Studio V8. See: https://PCBs.io/share/rG9GP

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Hi @Wijnand Do you have any conclussion? Have you tested it?. I do not see dht22 pinout, It has some built-in sensor for temperature and humidity?

@xz81 The second version (V2.0) is not tested yet, I am still waiting for the board, must arrive this week. Both parts (the VT-S02C with the CC1310 and the battery management (booster and power timer/switch) are tested seperately and that works. The combination test is for V2.0. The board is equiped with the MAX30205 (only temperature) but the pinheaders have al the communication pins (SPI, I2C, UART and ADC) for other sensors (as DHT22). There wil be a version V3.0 with PCB antenna and maybe not the VT-S02C ($4) but a normal CC1310 ($???).

Hi all, in the meantime the IoT LoRa v4 board (Arduino Pro Mini + RFM95W + AT24CXX:


and the IoT Battery-Sensor board (with the TPL5111/TPS22860 concept):


are tested and working perfect.

See also: IoT LoRa Sandwiches

The total result (with case 85x58x33mm and antenna) looks nice:



Just over a year too late… but yes, just to confirm the Whisper Node uses the RFM95 (20dBm), which Hope RF prints RF96 on their chips to confuse all of us. This is the same SX1276 chip on all other LoRaWAN devices and modules.

By the way, for those wanting to try the Whisper Node with TTN, have a look at the Adafruit TinyLoRa library. It should be just a matter of setting 4 things:

  1. The Frequency Plan directly inside TinyLoRa.h
  2. Manually add a device to your TTN Application and use ABP registration
  3. Open the example “hello_LoRa” and update the NwkSkey, AppSkey and DevAddr using the values generated by the TTN during your device registration
  4. Setup the correct pinout in the example code:
    // Pinout for Whisper Node LoRa
    TinyLoRa lora = TinyLoRa(2, 10, 7);

The library is not a full LoRaWAN implementation, but it’s indeed tiny:
Sketch uses 5232 bytes (17%) of program storage space. Maximum is 30720 bytes.
Global variables use 340 bytes (16%) of dynamic memory, leaving 1708 bytes for local variables. Maximum is 2048 bytes.

One more thing… you might need to keep eye/disable the “Frame Counter Checks” in the TTN or implement a way to save the counter as this starts from zero every reboot.

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