LinX HUMpro wireless device NO cmd response

I bought some of these to implement in a project, the support is pretty shabby and see no one on the internet using these to workout in their project!, I have the soldered joints working well as I get ,the following:

HUM-900-PRO v1.0.0 (C) 2014 Linx Technologies Inc. All rights reserved.

now, I have 2 modules working and spitting out the same when I start the module and if I reset them, meaning the joints are well formed.

(functioning of the device, Pulling the POWER_DOWN high and pulling the CMD high and sending byte data over Arduino UART should transmit the data given the conditions like 64byte default overflow register overflows and send the stuff over wireless! (there are other 3 ways but Im just using this for the time being))

One also needs to pull CMD line down on the HUMpro to make it know that it's actually a CMD coming and not data bytes coming in that the user wants to transmit wirelessly.

I cant get it to work at all! I should receive an ACK (0x06 if its ok ) NACK (0x15 its not ok)

tried sending FF 03 FE 02 to read a register less than 0x80 index but doesnt work, also tried various flavors like:

0xFF 0x03 0xFE 0x02 & 0xFF0x030xFE0x02 (with spaces without spaces Blah! Blah! various trials! but couldnt get it to work at all!)

Can ANybody dig into this and guide me where its not working?

I tried to attach the Data guide but due to upload limit that couldn't happen ,please have the link to it : Datasheet CUM Dataguide

Any heads up?

Bump!

I don't have and have never used these modules but from the data sheet you linked...

Since the module’s controller looks at UART data one byte at a time, the CMD line must be held low for the entire duration of the command plus time for ten bits as margin for processing. Leaving the line low for additional time (for example, until the ACK byte is received by the application) does not adversely affect the module. If RF packets are received while the CMD line is active, they are still processed and output on the module’s UART.

Are you holding CMD low for long enough and how is it held low? I don't see reference to needing pull up/down resistors on CMD line but maybe it's not being pulled down properly and needs an external pulldown resistor to hold it there?

Other than that I really don't have much of an idea.

Thanks Riva atleast you commented! with something pretty obvious but worth giving a second thought.

Are you holding CMD low for long enough and how is it held low? I don't see reference to needing pull up/down resistors on CMD line but maybe it's not being pulled down properly and needs an external pulldown resistor to hold it there?

I'm pulling it high by directly connecting it to vcc and pulling it down directly connecting the wire from the CMD to GnD, I think it maybe work trying using a resistor which I tried too, maybe Ill just try again.

Imay have to register this as a loss, s*o RIVA do you have any options and considerations for a 900mhz 915Mhz US norms OK wireless module?*

NI$HANT: I'm pulling it high by directly connecting it to vcc and pulling it down directly connecting the wire from the CMD to GnD, I think it maybe work trying using a resistor which I tried too, maybe Ill just try again.

If your pulling it low by connection directly to GND then the problem is not a floating pin on the arduino but I wonder if you have damaged something by connecting directly to VCC (or did you use a current limiting resistor). Do you use a 3.3V microcontroller or are you using 5V with some form of level shifting? I vary rarely use RF so not much help in suggesting an alternative.

IN the datasheet these folks have given a sample connectivity schematics which shows no current limiting also I have read they no where talked about a current limiter!

All logic level is 3v compliant.

NI$HANT: IN the datasheet these folks have given a sample connectivity schematics which shows no current limiting also I have read they no where talked about a current limiter!

Hopefully it is not relevant just a shot in the dark.

Riva,

There's some good news!

using the pullups on the CMD works!, the modules now send and receiver each other and the RFACTV led on my custom PCB lights everytime there's RF activity going on also as listed in the datasheet.

BUT,

I need to change the DSN addressing parameters because until unless there's an address match the modules wont SPIT what they received on UART lines for that I need to read and write the registers, I'm doing FF 02 FE 03 tp read register 3 to no avail! :'( (also tried 0xFF 0x02 0xFE 0x03 with spaces without spaces etc to o avail! also tried with carriage returns, \r, \n at the end to no avail!)

can you try and look into data guide that if there's something IM missing or not to how to format the commands.

I don't have a lot of time as packing for holiday but how are you sending the command codes? I think they are byte values and not character strings so you would need to use something like... Serial.write(0xFF); Serial.write(0x02); Serial.write(0xFE); Serial.write(0x03); and not... Serial.print("0xFF 0x02 0xFE 0x03");

Glad the pullup worked.

Serial.write(0xFF); Serial.write(0x02); Serial.write(0xFE); Serial.write(0x03); and not... Serial.print("0xFF 0x02 0xFE 0x03");

I was not using this way, because these folks defined that this can also work using directly connecting the uart to the serial converter and the same I did.

However I tried using your solution which looks more useful also but still no reply.