HM-TRP

[julianE]

Happy New Year to all.
I have been trying to get this module to work with a picaxe,

http://www.ebay.com/itm/HM-TRP-Wireless-Transceiver-433Mhz-HopeRF-w-simple-UART-Program-Interface-/171379880201

here is the datasheet for it,

http://hoperfusa.com/docs/HM-TRP.pdf

and here is a code I tried with it,

#picaxe 08M2
setfreq M32
'HM-TRP Transmit
pause 6000
sertxd ("start")
pause 6000

main:
for b1=1 to 100
	serout c.2,T9600_32,(b1)
	sertxd (#b1,CR,LF)
	pause 30000
next b1

goto main





#picaxe 08M2
setfreq M32
'HM-TRP Receive
pause 6000
sertxd ("start",CR,LF)
pause 6000

main:
serin c.1,T9600_32,b1
sertxd (#b1,CR,LF)
goto main

The receive side does print out data but it's not what I'm sending, I'm getting a series of numbers like: 252,249,248,253 and so on, nothing matching what I'm sending.
Also, the data is coming in perfect synch with the sending data so it's partially working.
I have looked on the forum for the module and most information is for an earlier version of this module.

I'm thinking I have to do something to configure the module, I do have an FTDI cable so I can attach to the modules and see if I can get it working. I tried using the utility from HOPE but am not having much luck with it.

Hopefully someone else has used this module and can help.

Thanks in advance.

 

[hippy]

I would guess the baud rate needs to be adjusted. I would suspect the modules are pre-programmed for 115,200 rather than 9600 baud.

 

[julianE]

Thanks for the quick reply. I tried using this utility to change the parameters using an FTDI cable,

http://www.hoperf.com/upload/rf/HM-TRP%20Setting%20GUI%20UserGuide_V01(english).pdf

It fails resetting the module or reading it. I did try changing the baud rate to 9600 while setup for communication at your suggested 115,200 rate, the red LED on the module does go off so it's doing something. I've tried every other baud rate and none seem to work as far as resetting the module. I don't think the picaxe can communicate at 115,200 rate but i have some raw pic chips and arduino i can try setting up for the high rate.
I don't think I have two bad modules but anything is possible. I might just have to put the module aside until there is more information on the web, it's very scarce at this time.

 

[hippy]

That document does suggest the default for the module is 9600 baud so not sure what the issue may be. If none of the baud rates the programming utility offers work there could be something wrong with the hardware or perhaps the modules have become reprogrammed with some non-standard baud rate.

I recall the datasheet suggested it had to have some pin pulled down to put it into configuration mode.

 

[julianE]

Yes, I had the configuration mode pin pulled down. I have seen other type of modules with non-standard baud rate so that's a possibility.
I'll keep searching for an implementation that works on a different micro controller platform. I can also try with two PCs using a usb to serial ttl adapter.