On the schematic print for the ESP32 LoRa 1 channel module, on the section concerning the RFM95HW the board RESET shows it going to “RFM_RST” how ever I can not find that reference to any pin on the ESP32-WROOM or any where else on the print for the matter.
Can some one tell me which pin on the ESP32 is connected to the RESET on the RFM95HW? I believe it is IO27 but would like confirmation.
Thank you for any assistance!
Have looked at this before. it does not seem to be connected to IO27. the RFM95HW reset pin is ONLY connected to the 10K pull-up to 3V3. I have checked the BRD file which shows that. I have also done a measurement with an ohm meter and that also shows the IO27 is NOT connected to the RFM95HW reset pin.
Thanks good to know. Sparkfun needs to clarify this issue. I saw a somewhat similar failure on an a competitors product, a while back, and when asked they responded within 2 hours and corrected the documentation immediately, as in same day.
The point to point that I have running does not apparently use the reset so probably not life and death to me. However when you investigated the BRD files am I to understand nothing is connected to the RESET pin? I will need to investigate that also if you don’t know. Many of the sample programs and libraries do call for a reset function so if that is not connected on this radio I understand why they don’t work with SF products.
There is only the 10K pull-up attached. The blue line runs from the RFM95 reset pin down to the resistor that is placed on the right hand side just underneath the ESP32 , just below pin 25, close to SCL and SDA pins
That said you are correct that as IO27 is NOT connected for reset, it should NOT be set as reset pin as on some places ( like in initLoraModem()) the rst pin is toggled to perform a reset. If anything else is connected to IO27… I don’t expect that will be appreciated. Better to set to zero.
Hi LRF.
As paulvha stated before, the reset line on the RFM69 is not connected to any I/O pin on the ESP8266. It’s permanently pulled high through a 10K resistor so that the RFM69 is never in a state of reset. From looking at the code and schematic, it appears that during development we may have originally intended reset be connected to a GPIO pin somewhere on the ESP32, but decided against it later on.
If you needed reset functionality, you could solder a small jumper wire to the reset pin on the RFM69 over to a free I/O pin. The picture below shows the appropriate pad on the RFM69 to connect too.
Thanks Chris, my only question here is in your response, you said, “the reset line on the RFM69 is not connected to any I/O pin on the ESP8266”, this module is suppose to be a RFM95 and it is paired with an ESP32?
Your fix of adding a jumper from RESET to a free IO pin would work, however disappointing in that it uses one of the limited number of free IO pins available. Seems to me it would have been taken care of at time of design and used one of the many other ESP32 pins not accessible to the user and handled in software and explained in complete documentation.
Thanks Chris, my only question here is in your response, you said, “the reset line on the RFM69 is not connected to any I/O pin on the ESP8266”, this module is suppose to be a RFM95 and it is paired with an ESP32?
My mistake, it is a RFM95 and not a RFM69. They both look very similar and I had the other module on my mind when I replied.
our fix of adding a jumper from RESET to a free IO pin would work, however disappointing in that it uses one of the limited number of free IO pins available.
Resetting the RFM95 isn’t needed by any of our examples and that may be one reason why it wasn’t ever connected. I’ll let our engineering team know customers are looking for this functionality and it may be added in a later revision.
Thanks
