I find IMP003 datasheet unclear regarding the current. Previously the datasheet specified: Normal operation, WiFi power-save mode enabled typ 8mA, max 250mA. In the latest datasheet that current is no longer specified. Why?
Can you share the expected current of IMP in these states?
IMP is sleeping
IMP is awake but not active and not connected to wifi
IMP is awake, super active, but not connected to wifi
We measure most of those numbers on an automated test rig for every software build (and several times each night, now over 10,000 runs total). For imp003 the answers are:
in deep sleep, too low to easily measure but chip vendor quotes 4uA
2a. with blink-up off, about 4.5mA but with a surprising amount of temperature variance (+/-1mA between summer and winter) which may or may not be an artifact of our test rig
2b. with blink-up on, about 25mA
about 50mA
(we don’t directly measure this, but during active transmit you can average 80mA with spikes even higher)
about 10mA average but with regular spikes above that
Note on 2: Peter’s numbers are for completely idle Squirrel with no peripherals configured. Once you configure UART, Sampler, FFD or PWMs then impOS can’t drop the clocks. I’m not 100% on SPI and I2C but they may also affect power.
Note on 5 and 6: There is also a significant amount of variance based on how much broadcast traffic is on the network since the imp has to process each of these to see if it is important. I would expect Peter’s numbers are near-best-case and that chatty networks would be higher power.
Well that’s right, it’s best to view those figures as lower bounds – there could be many reasons for not quite getting that low. For the record on clock-locking, currently the clocks are locked high during the following times:
when a UART is configured for receive (i.e. not NO_RX)
when a NO_RX UART is actively transmitting
when a SPI or I2C is actively reading or writing
when the sampler or FFD is running
when a PWM is configured
when Squirrel code is executing
when blink-up is enabled
That last one means that much of the 20mA difference between my quoted 2a and 2b numbers is due to the clock-locking -- it's not all drawn by the LEDs.
Thanks for your comments. It is very useful input. I learned that current is a bit more complicated and that modeling the battery lifetime of our product must be based on actually measured currents.