Re: Frequency hopping experiments on the NRF24
Posted: 17 May 2020, 22:15
Yes, if you know you have a good ESC with a reliable 5V BEC output, then it's best to power the RF-Nano from that, into the RF-Nano's VCC (5V) pin.
The only reason I suggest possibly using the Vin (or Raw) input is if you have a 5.5V or 6V BEC, or I've seen some switch-mode BECs that have very noisy 5V output - especially when the motor is running about half-throttle. In these cases it might be better to feed the RF-Nano into its Vin (Raw) input from the main flight power pack: direct for a 2-cell pack, or via a dropper diode (or LED) for a 3-cell pack.
It does complicate the wiring though, so if you have a good reliable 5V BEC, keep things simple and power all the radio gear from that, as Phil suggests.
It's important NOT to power the RF-Nano from 5V into its Vin (Raw) pin: although it would most likely work, the on-board regulator drops about a volt, so the RF-Nano, including its nRF24L01 would then be running at only 4V. The chips would probably work okay at this, but it's outside the spec of the main Atmel chip to run at 16MHz from only 4V, so it wouldn't be as reliable.
The only reason I suggest possibly using the Vin (or Raw) input is if you have a 5.5V or 6V BEC, or I've seen some switch-mode BECs that have very noisy 5V output - especially when the motor is running about half-throttle. In these cases it might be better to feed the RF-Nano into its Vin (Raw) input from the main flight power pack: direct for a 2-cell pack, or via a dropper diode (or LED) for a 3-cell pack.
It does complicate the wiring though, so if you have a good reliable 5V BEC, keep things simple and power all the radio gear from that, as Phil suggests.
It's important NOT to power the RF-Nano from 5V into its Vin (Raw) pin: although it would most likely work, the on-board regulator drops about a volt, so the RF-Nano, including its nRF24L01 would then be running at only 4V. The chips would probably work okay at this, but it's outside the spec of the main Atmel chip to run at 16MHz from only 4V, so it wouldn't be as reliable.