Nordic FOB battery life problem

Wireless & IoT
1

I’ve been using two of the Nordic FOBs in a prototype. They both work identically, but one of them eats batteries (<1 hour battery life). The other goes for days/weeks on a single cell. They seem to be different design versions, but I can’t see an obvious difference between them.

The PCB of the “good” one is dated 10/29/08. The PCB of the one that eats batteries is dated 3/17/08. That one has a constant impedance of about 220 ohms from VCC to GND; the other one is much higher. The Atmel fuses are the same.

Is there a difference in the semiconductor components (Atmel and Nordic) that would account for this? Can I order a new one and get the new version?

2

Actually, the bad fob has an nRF24L01 on it, not the + part (SparkFun was clear they were the L01+ when I ordered them…). That part has a different protocol for entering standby mode, which probably explains the problem.

I’ll put it in standby and get a replacement with L01+.