Power requirements confirmation

It looks like the H7 is speced to draw a little less power than the M7: (idle-no-card/idle-w-card/active-no-card/active-w-card) 110/110/190/200 for the M7 and 110/110/160/170 for the H7. Is that correct?

The LCD shield is speced to draw (idle-light-off/idle-light-on/active-light-off/active-light-on) 1/30/10/40 or alternatively “with cam” 100/130/150/180. I don’t understand “with cam”. Clearly it can’t indicate the combined power of the LCD and the camera since it is lower than the camera alone in some of the 8 combinations between the two cameras, so presumably this is the power consumption only of the LCD when it is connected to a camera, right?, More to the point, is the “not-with-cam” power data essentially not representative of any real use case (since when would you use the LCD without the camera?) and only the “with cam” data representative of a normal scenario in which the shield is attached to the camera – or is there some practical interpretation of “not-with-cam” that makes sense?

Bottom line, should I assume that a combined camera/LCD setup can draw up to 380 total for an M7 (200+180) and 350 (170+180) for an H7? Or am I not understanding correctly? Thanks.

Moving on, the WIFI shield is speced at 80/100 idle/active (or, again confusingly as with the LCD shield, 180/200 “with cam”, which again doesn’t make sense interpreted either of the two ways (1) the shield draws an additional 100 just for being attached to the camera or (2) the the sum of the shield and the camera is perplexingly no where near the sum of the camera and the shield’s “not-with-cam” values). In any case, an idle/active spread of only 25% is shocking. Other wifi devices, like the ESP8266, have dramatic swings in power consumption because, as anyone would expect, it takes a garbage truck of power to enthusiastically transmit a radio signal. But the OpenMV WIFI shield claims to have a marginal spread between idle and active, only increasing its power consumption by 25% when transmitting. What am I misunderstanding here?

I’m asking all of this because I want to couple an OpenMV with various ESP8266 boards and it would be nice to combine the power into a single cable having one of the two devices power the other off its rails. Since OpenMV can only provide 250 of 3.3 and can’t offer 5 at all if an external device needs it, while ESP8266 devices can easily outdraw the 250 limit, I’m left with the option of powering the OpenMV off the wifi board’s rails, so of the various boards I might consider, I want to know which ones can provide OpenMV’s power requirements.


Please write less dense forum posts. :wink:

The specs are for the total system. The LCD shield draws only a few mA.

I write thorough questions to avoid responses of the “go read the docs” variety. If the docs are confusing, or even potentially inconsistent, I ask clarifying questions.

I suppose that since I’m still ramping up on building the firmware (I think may have succeeded actually, I need to run some tests), a different way I could help out is to edit and improve the docs whenever I gain clarity on various issues.


I fully understand the challenge of writing, much less maintaining, documentation. That’s why I’m offering to contribute.

Sent you an email.