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R9M Inverter Mod

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  • To benefit from the higher bitrate of 400 kilobit per second using OpenTX you need to add a pullup resistor to the inverter of the serial port on the R9M 2018🗻🆙
  • Strongly suggested to be done for anybody looking for higher than standard packet rates using ExpressLRS 🔮


⚠️ This is only required for the 2018 version of the module which has a ACCST logo on the case 🔍


Easy - connect a 300Ω to 1000Ω resistor between the 3.3V and inverter pin as shown on the picture 👧

Transmitter Notes

  • X9D only does 400 kbit/s and does not allow lowering the bitrate to 115200 bit/s - 400k Mod is not required.
  • X10S Express 400k Mod is not required.
  • X10S modification is required 🙅
  • X12 modification is required 🙅
  • QX7 allows configuration of the bitrate in the OpenTX hardware menu. ELRS will work fine using 115200 bit/s but the modification is required for 400 kbit/s 🙅‍♀️
  • The modification is not needed for ACCESS radios