Help using enhanced shockburst for the NRF24L01

[teletype-guy]

Hey Unex:

It is really not that complicated. You have a pic running at 5V and a peripheral (24L01) running at 3.3V.

Since the peripheral has 5V-tolerant inputs (no upper clamp diodes on the inputs), there is no problem sending 5V signals to it to it.

The 3.3V out of the 24L01 can go to a TTL-COMPATIBLE input (VIH = 2.0V) on the pic, if you have one available, with no problem.

If your pic input has cmos thresholds (VIH ~= 3.5V), then you need to add a gate in between. Connect your 3.3V signal to the input of a 5v-POWERED AHCT gate (or HCT in a pinch), and connect the gate output to the pic. You will want a non-inverting gate (or two inverters in series, or change your code for an inverted level...).

Check the DC spec on each pic input and it will tell you if the pic input pin has ttl or cmos thresholds.


gil