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Show HN: I made a tiny camera with super long battery life
71–80 of 309 posts
Re: Show HN: I made a tiny camera with super long battery life
#72Earlier quoted context omitted.
Can I ask why you went with a MSP430? I'm not judging, they were all the rage in low-power embedded applications 10-15 years ago, just feels weird to see it in a modern design today, when the market now is flooded with low-power ARM chips that are way more capable than that, and probably easier to program.
Not the OP, but my understanding (admittedly a few years outdated) is that an MSP430 will, in idle, with sleep states properly set up and low power modes in use, drain a coin cell battery (e.g. CR2032) over a period of years - with the current drawn around 1.5 uA in standby and 0.1uA in RAM retention idle. That is likely even lower than the effective self discharge rate of a lithium coin cell battery. I don't believe…
> That is likely even lower than the effective self discharge rate of a lithium coin cell battery.
That's what I've found too. Based on my measurements and calculations, Photon uses 5µA (MSP430 + motion sensor) while sleeping, while the battery's self-discharge is more like 80µA.
That's probably a good argument for using a more powerful chip though, if the battery self-discharge is that high, hah.
Re: Show HN: I made a tiny camera with super long battery life
#73Earlier quoted context omitted.
Can I ask why you went with a MSP430? I'm not judging, they were all the rage in low-power embedded applications 10-15 years ago, just feels weird to see it in a modern design today, when the market now is flooded with low-power ARM chips that are way more capable than that, and probably easier to program.
One main reason I chose the MSP430 was for the FRAM. Photon stores all its state (ie the photo ring buffer indices, and user settings) in one big FRAM struct, which can be read/written just like RAM, but persists across power cycles and crashes. Another reason was MSP430's low power consumption, but like you said it sounds like ARM has caught up. Would love to hear about alternative designs -- are there low-power ARM…
If external F-RAM is an option, one can use F-RAM from, say Cypress (now Infineon, [1]) together with ARM chips from Ambiq, e.g. Apollo 3 Blue Thin [2], which likely have even better power consumption than an MSP430.
[1] https://www.infineon.com/cms/en/product/memories/f-ram-ferro...
Re: Show HN: I made a tiny camera with super long battery life
#74I really appreciate the considerations at the bottom of the page. Excellent
Re: Show HN: I made a tiny camera with super long battery life
#75Earlier quoted context omitted.
One main reason I chose the MSP430 was for the FRAM. Photon stores all its state (ie the photo ring buffer indices, and user settings) in one big FRAM struct, which can be read/written just like RAM, but persists across power cycles and crashes. Another reason was MSP430's low power consumption, but like you said it sounds like ARM has caught up. Would love to hear about alternative designs -- are there low-power ARM…
If external F-RAM is an option, one can use F-RAM from, say Cypress (now Infineon, [1]) together with ARM chips from Ambiq, e.g. Apollo 3 Blue Thin [2], which likely have even better power consumption than an MSP430. [1] https://www.infineon.com/cms/en/product/memories/f-ram-ferro... [2] https://ambiq.com/apollo3-blue-thin/
Dang very cool. If there's ever a Photon 2 I'll definitely look at the low-power ARM world.
(FWIW Photon's USB stack is handled by a STM32F730 and I've been perfectly happy with it. Expensive though.)
Re: Show HN: I made a tiny camera with super long battery life
#76I'm not interested in the product, but I have to say this site is great. Too many sites that get posted in Show HN are so difficult to decipher what service they provide or function they serve. This landing page is about as clear as you could be straight away: it's a small camera -> great battery life -> pricing (without going to another page!) -> Mac Only -> Buy/Download links. You provide use cases, your tech specs…
That means a lot, thanks friend.
Re: Show HN: I made a tiny camera with super long battery life
#77Few questions come to mind: - what’s the image resolution? Is it fixed or can it be changed in the settings? - can you attach an actual image file? The previews are barely clear to show anything. - any info about operating temperature? The battery might not die but the camera shuts off due to high temperatures, happens to me all the time with gopro and the likes. - what’s the storage capacity? Not mentioned anywhere.…
Until I add some good imagery to the site, you can see real imagery in the demo mode of Photon Transfer:
Re: Show HN: I made a tiny camera with super long battery life
#78> exclusively for Mac Why not just have it connect as a generic mass-storage device?
Totally fair question! My reasons were: 1. To maximize Photon's battery life I tried to make the hardware do the absolute minimum to record imagery. To that end, Photon stores images on an unformatted SD card (ie one huge linear array of bytes) which is easy and fast to index into. 2. A 16-bit MSP430 handles writing the image data, and the MSP430's codespace is 99% exhausted without dealing with the complexities of a…
Love these answers. I declare you officially to be a badass.
Re: Show HN: I made a tiny camera with super long battery life
#79What an excellent post. I love it and learned so much.
Would you be willing to share a ballpark price for what you pay for the enclosure? And maybe ballpark how many you ordered at once? I have found getting enclosures made to be incredibly expensive -- but I have only ever done VERY low volumes (5-10).
Re: Show HN: I made a tiny camera with super long battery life
#80> A few years ago someone kept trying to steal my motorcycle, so I decided to make a small camera with really long battery life to catch them. The camera seems really cool. But given that the device has no way to get photos off it without physical access, it seems like this wouldn't be super useful for your original purpose. If someone just takes the camera (or manages to successfully steal your motorcycle), then the…
I don't think the camera goes on the motorcycle.
Yeah my plan was to hide it in the garage's rafters. (I ended up moving out of my apartment complex anyway though, so I ended up not needing it for that anyway.)