UM96 spits out random characters occasionally

Wireless & IoT
1

Hey there - I am using a couple Haccom UM96 modules from SFE. I’ve noticed that though they work fairly well, I do periodically see strings of completely garbled data. Connecting a serial cable directly to the remote board (instead of using two UM96s in between) solves the problem. I would think this is normal with wireless data transmission, except that in the product description it very specifically says

“All buffering and error detection is handled internally.”

This seems to be a false statement. Anybody else have similar experiences? It’s not a constant problem - I see it in maybe 1/100 characters. It’s enough that it’s a nuisance.

2

I’m having a similar experience.

I have two UM-96’s connected to Parallax Propellers, and PC to monitor what is begin exchanged over the wireless link. One Prop sends a message with a sequence number, the other sends the sequence number back, and so on…

Every so often a message gets "lost’ and sometimes characters in the message gets repeated.

I suspect as well that the datasheet is wrong - it does take care of getting the data from one end to the other.

I am going to implement a “higher” protocol to cover lost/duplicate data.

Mike