Gateway sends NACK to node

[mariusl]

Thanks I will give that a try.

[mariusl]

This is very strange but could indicate where to look for similar problems. I dumped the mysensors gateway and node and programed the arduinos with the standard arduino Lora libary to establish a serial device on HA. This worked first time and I could get messages through, no problem. This means that the radios was at least working. Then I reprogramed the gateway and the node with mysensors serial GW and node options. The radios connected first time and I don't think I received a single NACK for two days now.
So I can only think that there must be some radio setup parameters that are stuck in memory or something like that.

Any ideas from someone on this?

[ctodor]

same issue here. i can not pair a gw and a node.
there are a lot of "open issues" regarding gw/node paring => something is wrong in this design, it tries to cover too many platorms but it doesn t do it in simple/good way for neither one

[mariusl]

I think what is required is maybe an option to erase all memory or config if a flag is set. This will make sure that the chosen radio config will be correct.

[yury]

@mariusl said in Gateway sends NACK to node:

Any ideas from someone on this?

#define MY_TRANSPORT_STATE_TIMEOUT_MS (5*1000ul)

//#define MY_RFM95_MODEM_CONFIGRUATION RFM95_BW125CR45SF1288
#define MY_RFM95_MODEM_CONFIGRUATION RFM95_BW125CR48SF4096

These lines can affect. the TRANSPORT_STATE_TIMEOUT may be less than a actual message sending time. you will get constant NACK's.

[mariusl]

@yury said in Gateway sends NACK to node:

These lines can affect. the TRANSPORT_STATE_TIMEOUT may be less than a actual message sending time. you will get constant NACK's.

I have it working fine now but I would like to make it as robust as possible. What would you suggest as a good value for the timeout?

[yury]

@mariusl said in Gateway sends NACK to node:

good value for the timeout?

here are the delay examples in the docs
https://www.mysensors.org/apidocs/group__RFM95grp.html#ga23a30185cbd40984e65d5269983bf840

for yours #define MY_RFM95_MODEM_CONFIGRUATION RFM95_BW125CR48SF4096

I would use #define RFM95_RETRY_TIMEOUT_MS (2000ul)

any reason for the Spread factor SF4096 ?

[mariusl]

@yury said in Gateway sends NACK to node:

any reason for the Spread factor SF4096 ?

Not at all. It is from example code that I found online. I don't really know what it does to be honest.

[yury]

@mariusl said in Gateway sends NACK to node:

what it does

SF number is chips (chirps) needed to code each bit. SF4096 is maximum range especially in urban area, but very long delay . I tried different combinations and found below MY_RFM95_MODEM_CONFIGRUATION is pretty much good. 20 - 30% less in terms of distance and delay #define RFM95_RETRY_TIMEOUT_MS (300ul) is enoght. Much faster.

#define MY_RFM95_MODEM_CONFIGRUATION RFM95_BW_500KHZ | RFM95_CODING_RATE_4_5, RFM95_SPREADING_FACTOR_2048CPS | RFM95_RX_PAYLOAD_CRC_ON, RFM95_AGC_AUTO_ON

[mariusl]

Aah ok that makes sense. My application is for rural use and I need the max distance possible. The slow response will not be a problem as the sensors don't send a lot of data at all. So maybe I will stay with the SF4096 for now but I will do some experimenting with the settings. Just to understand them a bit better.