# Error in LoRa Gateway: failed to start the concentrator **URL:** \ **Category:** Raspberry Pi Gateways\ **Created:** [December 20, 2018, 6:27pm UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887 "2018-12-20T18:27:54Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![KAljehani](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kaljehani/32/20484_2.png) [@KAljehani](https://www.thethingsnetwork.org/forum/u/KAljehani)\ **Post date:** [December 20, 2018, 6:27pm UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/1 "2018-12-20T18:27:54Z")
Hi, I am running a Semtech basic packet forwarder on RPI3 + RisingHF LoRa Gateway module. After I reset the gateway, I run the packet forwarder and this error is displayed: **ERROR: [main] failed to start the concentrator** After I couple of consecutive tries of running the packet forwarder, it works. What is the cause and solution of this issue? Best regards ---
**Author:** ![Jeff-UK](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jeff-uk/32/35697_2.png) [@Jeff-UK](https://www.thethingsnetwork.org/forum/u/Jeff-UK)\ **Post date:** [December 20, 2018, 7:04pm UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/2 "2018-12-20T19:04:30Z")
Checking the correct RPi pin assignment for the concentrator card is usually 1st stop - often 5, 17 or 25 depending on iMST or Rak based build - dont know which is correct for RisingHF module as haven’t used one myself - should be called out in the documentation - be sure not to mix physical pin with Broadcom logical pin - and may be juggled by any interposer card (again check docs) if not hard wired directly (not recommended due to interference pick up on flying leads ;-). Check setting in startup script. Also may make sense to limit/constrain SPI clock by setting @ 250 (GIYF) if not already done…good luck! ---
**Author:** ![kersing](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kersing/32/44777_2.png) [@kersing](https://www.thethingsnetwork.org/forum/u/kersing)\ **Post date:** [December 20, 2018, 7:30pm UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/3 "2018-12-20T19:30:32Z")
> [@KAljehani](#): > > solution of this issue Search the forum. This is not a new issue and it has been answered multiple times. (Or thank Jeff-UK for providing you a short cut to the answers) ---
**Author:** ![KAljehani](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kaljehani/32/20484_2.png) [@KAljehani](https://www.thethingsnetwork.org/forum/u/KAljehani)\ **Post date:** [December 22, 2018, 10:45am UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/4 "2018-12-22T10:45:45Z")
I really appreciate your respond Regarding SPI clock, can you show me how to set to 250? I have doubts that it’s the problem. Note: the gateway is working 100% after multiple tries of starting the packet forwarder. Best regards. ---
**Author:** ![KAljehani](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kaljehani/32/20484_2.png) [@KAljehani](https://www.thethingsnetwork.org/forum/u/KAljehani)\ **Post date:** [December 22, 2018, 10:46am UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/5 "2018-12-22T10:46:52Z")
I already searched, and did not get the answer that solve my issue. I appreciate your help ---
**Author:** ![Jeff-UK](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jeff-uk/32/35697_2.png) [@Jeff-UK](https://www.thethingsnetwork.org/forum/u/Jeff-UK)\ **Post date:** [December 22, 2018, 11:42pm UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/6 "2018-12-22T23:42:19Z")
GIYF “raspberry pi SPI 250” or search this forum “SPI 250” - 1st hit (ref RPi3 & iMST concentrator tells much!) If using mp pkt forwarder potentially also look to add the -s option if you see further problems 😉 ---
**Author:** ![TonySmith](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/tonysmith/32/46334_2.png) [@TonySmith](https://www.thethingsnetwork.org/forum/u/TonySmith)\ **Post date:** [December 23, 2018, 3:42am UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/7 "2018-12-23T03:42:52Z")
try adding “core\_freq=250” to /boot/config.txt this will lock the SPI speed to 8MHz. Search for VPU in the discussion “rp3-x-ic880a-gateway-stopped-working” ---
**Author:** ![KAljehani](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kaljehani/32/20484_2.png) [@KAljehani](https://www.thethingsnetwork.org/forum/u/KAljehani)\ **Post date:** [December 23, 2018, 11:02am UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/8 "2018-12-23T11:02:06Z")
> [@Jeff-UK](#): > > raspberry pi SPI 250 Thanks. The post you referenced helped to understand the issue. ---
**Author:** ![KAljehani](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kaljehani/32/20484_2.png) [@KAljehani](https://www.thethingsnetwork.org/forum/u/KAljehani)\ **Post date:** [December 23, 2018, 11:03am UTC](https://www.thethingsnetwork.org/forum/t/error-in-lora-gateway-failed-to-start-the-concentrator/20887/9 "2018-12-23T11:03:55Z")
I really appreciate your effort & reply I modified core\_freq=250 but nothing changed. I will review it later. My solution is to keep trying till packet forwarder works Thanks to all of you!