Hi, I have a set of the 433MHz RCTimer telemetry radios and have noticed the noise level on the ground radio is about 20 units higher than the air module (due to onboard FTDI chip) which is limiting potential range.
I had a look at the datasheet for the HM-TRP module and was wondering.. would it work if I de-soldered the HM-TRP from the RCTimer board and connected it directly to a 3.3v FTDI adaptor via a longer lead (and set the Config pin high and the Enable pin low)?
Thanks
Replies
1 are you sure your ground module still working /communicate with its pair air module or other radio?
2 you are using 3 black wire that might mixed you up between GND, TX RX
3 your source of 5 volt MUST not come from USB computer but try to find cell phone charger
as pure 5V and ground no DATA
I'm powering all of my "homemade" 433MHz HM-TRP 3DR radios from USB-UART converter (i. e. FTDI, Prolific or SiLabs) without ANY noise issues, so that's not a problem.
Dear Marcin,
by reading many blogs I found out that you are one of the most experienced users for wireless data transmission.
I have one specivic question and I must explain my previous experiences.
For a weather projet I need to send the data from the sensor (outside) to the receiving station (inside). I like to use the 868 Mhz band and I am limited to 2.400 baud no parity.
The communication is betwen two MCUs not MCU and PPC
I purchased several transceiver including the HM-TRP module (OEM) version. None of them are not working. The HM-TRM can be configured but I do not have the experience and the equipment to configure the device
Now my question:
Can I buy from You two transceivers, tested for 2.400 bauds no parity transmission, in the 868 Mhz band?
I am glad to hear from you soon.
Best regards
Werner
Dear Marcin,
thank you for the fast response. You have been my last hope. I could not go above 2400 BAUDS. It is almost impossible to find a wireless modem for 2400 baud.
The only solution might be a RF transmitter and receiver. The 433 Mhz are not working because my Max 7219 produce too much EMI. The last trial is to purchase one RF set for 868 Mhz. Hopefully I find a high quality pair.
Best regards
Werner
I can sell 868 modems, but I'm afraid that 4800bps is lowest baudrate possible...
Or do you mean air rate?
http://copter.ardupilot.com/wiki/common-3dr-radio-advanced-configur...
Serge
it is clear you can see the parameter of 3DR radio using 3DR Radio Config Software by clicking load setting and both parameter
"Local Version" and " Remote Version" have same Value
Meaning Both Radio ground and ground Mod working ok
First Solution
if you see SIK 1.9 try to downgrade to 1.8 or 1.7
I had experience stop transmitting but halfway.
Second
I saw you bypassed soldering wire direct to the pad of HM-TRP Module.
like many people did/ suggest at many thread. I think that is not 100% correct even the radio working and .especially noise level at SIK 1.9 is higher by default setting that can cause connection problem
Comparing to eagle files of 3DR radio before TX and RX from FTDI chip.
This is the part number you need before soldering to those TX and RX pad
(BLM15HD102SN1 Noise Suppression Products/EMI Suppression Filters)
Marcin
Seems that you have followed this Radio Modification.
I need some modification for this USB module for extra longer and lower noise mine is 915Mhz and this noise filter is too small as inductor type filter to working with.
Any other suggestion .? thank you
3DR-Radio-USB.zip
Thank you for the input naitsuga, I'll try to do this once I get the filters.
Regards,
Serge
For both 433 and 868 I'm using ONLY single 3,3V linear voltage regulator with 2 ceramic 1uF capacitors and 4 pcs. of CBW160808U102 (https://www.maritex.com.pl/media/uploads/PRODUKTY_PDF/pas/FHCBWv2.pdf) for data lines, it works like a charm.
Yes the ground module is still communicating with its pair. Actually, I am able to use the radio config page and load the settings of this ground mod turned air mod successfully. It just doesn't load parameters when I click the connect button.
On another spare module, I am using a color coded wire same as Iskess.
ok your are trying to configure the air module via Ground module using the 3DR radio Config software?
let me be clear with you do you have real air module that already connected to the APM?
or your are about to modify the ground to become air module as a spare unit or second unit?