[chbot] I started a kickstarter for my Binary watch

Charles Manning cdhmanning at gmail.com
Wed Aug 13 20:09:51 BST 2014


PICAXE is fine for high school hobby projects but it is rubbish for
any real product.

If you're going to use LiIon then you need a proper charge & discharge
circuit. If you treat them like you are they will:

(a) die in weeks --> pissed off customers.
(b) burn houses down --> more pissed off customers, happy lawyers though.

That micro I mention actually has a built in RTC too. I forget the
sleep/RTC current consumption, but it is in the few microAmps
department. It does, however, need some skill to use.


On Thu, Aug 14, 2014 at 4:20 AM, William Fleete <fleetwil at gmail.com> wrote:
> I think I want to make it use an RTC chip to do the actual timekeeping, that way it can keep time off a coin cell and the PIC/Atmel/Arm or whatever running off a rechargeable LiPo/ion, the RTC would last years on the coin cell and if the LEDs were used moderately and the beeper off possibly a (several) week(s) - month(s) on the rechargeable depending on the capacity I can fit in the final case, the controller would be pretty much just be monitoring an input in sleep mode and be basically the quiescent current of the (accessory) chips (pretty much just the LiPo monitor and the controller) I know the quiescent current of the old watch with a PICAXE 20 and 3 UCN5841 registers is about 3 mA and lasted around 5 days to a week even with the beeping although I was hard on the crappy LiIon letting it go dead flat (less than 2 volts) and not really charging it correctly and is partly why I started this.
>
> Sent from my iPad
>
>> On 13/08/2014, at 20:46, Charles Manning <cdhmanning at gmail.com> wrote:
>>
>> If you want something different then why not go for a binary watch or
>> similar that has some other coolness like Bluetooth LE.
>>
>> A 32-bit ARM BTLE micro that runs for over a year on a coincell might
>> be a good idea.
>>
>> See NRF51822. They cost around $2.20 USD. Add a crystal and a few
>> passives and you have a full Bluetooth LE device that can talk to
>> iphones etc etc etc. You could make these into watches at reasonable
>> volumes for $10-$20 each.
>>
>>
>>> On Wed, Aug 13, 2014 at 6:35 PM, Ian Tennant <i.tennant at xtra.co.nz> wrote:
>>> You might find this link interesting, especially the price!!  Not as
>>> function –rich as your proposal though. Good luck with the project.
>>>
>>> http://www.chinavasion.com/china/wholesale/Electronic_Gadgets/LED_Watches/Cheap_LED_Watch
>>>
>>>
>>>
>>> From: chchrobotics-bounces at lists.linuxnut.co.nz
>>> [mailto:chchrobotics-bounces at lists.linuxnut.co.nz] On Behalf Of William
>>> Fleete
>>> Sent: 13 August 2014 16:22
>>> To: Christchurch Robotics
>>>
>>>
>>> Subject: [chbot] I started a kickstarter for my Binary watch
>>>
>>>
>>>
>>> I'm going to have a go at improving on my binary watch which some of the
>>> members may know about, so I've started a kickstarter project, it would be
>>> great if you could pledge and I will need some assistance with some of the
>>> prototyping, design and possibly the coding for the micro controller, the
>>> PICAXE code is all well and good but adapting it to a PIC or similar will be
>>> a process, and I don't have the facilities to etch PCB's or 3D print items.
>>> It would be great if you all help out.
>>>
>>> I'm on crutches now so I may be able to come to the next meeting
>>>
>>> Link to the project below
>>>
>>> http://kck.st/VhPh5E
>>>
>>>
>>> _______________________________________________
>>> Chchrobotics mailing list Chchrobotics at lists.linuxnut.co.nz
>>> http://lists.ourshack.com/mailman/listinfo/chchrobotics
>>> Mail Archives: http://lists.ourshack.com/pipermail/chchrobotics/
>>> Web site: http://kiwibots.org
>>> Meetings 3rd Monday each month.
>>>
>>> When replying, please edit your Subject line to reflect new content.
>>
>> _______________________________________________
>> Chchrobotics mailing list Chchrobotics at lists.linuxnut.co.nz
>> http://lists.ourshack.com/mailman/listinfo/chchrobotics
>> Mail Archives: http://lists.ourshack.com/pipermail/chchrobotics/
>> Web site: http://kiwibots.org
>> Meetings 3rd Monday each month.
>>
>> When replying, please edit your Subject line to reflect new content.
>
> _______________________________________________
> Chchrobotics mailing list Chchrobotics at lists.linuxnut.co.nz
> http://lists.ourshack.com/mailman/listinfo/chchrobotics
> Mail Archives: http://lists.ourshack.com/pipermail/chchrobotics/
> Web site: http://kiwibots.org
> Meetings 3rd Monday each month.
>
> When replying, please edit your Subject line to reflect new content.



More information about the Chchrobotics mailing list