I have been playing around with changing the bit-rate from 1200 to 4800(default) to get the best range in a long distance vertical run. Obviously 1200 gets the best distance but for a battery powered solution where I need ACKs, it takes too long. Ideally I would like to use the default settings but extend the range if its possible with a settings change. Here are my settings and findings, is there anything I can do differently?
4800 - Default settings
radio.writeReg(0x58, 0x2D);
2400 settings:
radio.writeReg(0x58, 0x2D);
radio.writeReg(0x03,0x34); //RegBitrateMsb 2400 bitrate
radio.writeReg(0x04,0x15); //RegBitrateLsb 2400 bitrate
radio.writeReg(0x05,0x00); //RegFdevMsb 2000
radio.writeReg(0x06,0x52); //RegFdevLsb 2000
radio.writeReg(0x19,0x40|0x10|0x05); //RegRxBw DccFreq:010, RxBw_Mant:24, RxBw_Exp:5
radio.writeReg(0x18,0x00|0x00|0x01); //RegLna LnaZin:50ohm, LowPower:Off, CurrentGain:MAX
1200 settings:
radio.writeReg(0x58, 0x2D);
//radio.writeReg(0x03,0x68); //RegBitrateMsb 1200 bitrate
//radio.writeReg(0x04,0x2B); //RegBitrateLsb 1200 bitrate
radio.writeReg(0x05,0x00); //RegFdevMsb 2000
radio.writeReg(0x06,0x52); //RegFdevLsb 2000
radio.writeReg(0x19,0x40|0x10|0x05); //RegRxBw DccFreq:010, RxBw_Mant:24, RxBw_Exp:5
radio.writeReg(0x18,0x00|0x00|0x01); //RegLna LnaZin:50ohm, LowPower:Off, CurrentGain:MAX
I got rid of sendWithRetry and used standard send and receive in while loop to time the difference in TX / RX timing.
4.8Kbps Timing Test:
13 [RX_RSSI:-35
ms to receive message: 7
ms to Transmit message: 4
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14 [RX_RSSI:-35
ms to receive message: 6
ms to Transmit message: 6
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15 [RX_RSSI:-35
ms to receive message: 6
ms to Transmit message: 4
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2.4kbps Timing Test:
251 [RX_RSSI:-33
ms to receive message: 92
ms to Transmit message: 84
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252 [RX_RSSI:-33
ms to receive message: 88
ms to Transmit message: 84
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253 [RX_RSSI:-34
ms to receive message: 145
ms to Transmit message: 84
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1.2kbps Timing Test
3 [RX_RSSI:-34
ms to receive message: 172
ms to Transmit message: 168
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4 [RX_RSSI:-34
ms to receive message: 172
ms to Transmit message: 166
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5 [RX_RSSI:-33
ms to receive message: 170
ms to Transmit message: 168