PULS: A low-cost programmable oscillator or pulse generator - Page 1
Forum section: electronics / general

author: Stathera
author_rank: Newbie
timestamp: September 25, 2020, 05:34:16 am
content: Hi,I have just started a KickStarter project for PULS: Low cost programmable oscillator and pulse generator chips. The link to the project ishttps://www.kickstarter.com/projects/stathera/programmable-oscillator-and-pulse-generatorExcerpts from the Kickstarter site:MotivationHave you ever needed an oscillator or one-shot at some reasonably low frequency (e.g. < 1MHz or > 1ms) and modest accuracy? Of course, we nearly all have. Usually, three options present themselves: (a) 555 timer chips or relatives (b) relatively expensive integrated circuits (e.g. LT-6995) (c) micro-controllers with custom code.While these are all valid solutions, they are hindered by drawbacks. For example, a 555 timer is low cost but it usually needs two external resistors and capacitors. Also for very low frequencies (e.g. < 1mHz) those capacitors can be big and clunky.Integrated circuits work well and have a small footprint but they are expensive (e.g. LT-6995 is ~$3.50 in QTY:1 and ~$2 in QTY:500) and even still require an external resistor and you need different chips if you want a one shot versus an oscillator.Micro-controllers work well and they have a small footprint and usually don’t require external timing resistors/capacitors but you have to write custom machine language code for each application—especially if you want accuracy. Even worse, if your specs change, you have to rip the code up and write-it a new.Basic DescriptionWe have created a new option which combines the best of all options. The PULS-1 system allows you to create either (a) an oscillator with adjustable duty cycle and frequency from ~1mHz to ~500kHz or (b) a pulse generator with re-triggerable and delay options with delays/pulse widths from more than 10 days down to 1 micro-second.You plug a DIP-8 or SOT23-6 chip into the programming socket and select the specifications using the easy-to-use software. The PULS-1 system programs a PIC-10F-200 micro-controller to automatically implement the desired function. The system covers VDD from 2V-5.5V and temperature from 0 to 50degC and can drive loads up to 3mA and sink loads up to 8mA. The basic accuracy is +/- 0.2% at VDD=5V and T = 25degC and +/- 1% over 0-50 degC.Please watch the video for example operation and cases on the kickstarter site.I would appreciate if you could support my project on kickstarter. If you have any questions or comments, feel free to let me know.Brian @ Stathera, LLC

author: PlainName
author_rank: Super Contributor
timestamp: September 27, 2020, 12:52:22 am
content: A bit of a different project with some good thought put into it!It seems to me the magic is mostly in the application software. $100 for a one-off chip is rather steep, and if you're going to need a lot of them then investing in programming something yourself is probably appropriate. It's not as if you can twiddle a knob once it's in-circuit and change the parameters on the fly. So it's that ability to set the type and values without programming that's the USP, but it comes at rather a high cost.It's not completely clear from the Indy page (at least to me) whether you can use an off the shelf PIC (that is, the application essentially writes all the code to implement the requirements, then programs a clean chip), or if they have be chips supplied by you (i.e the application talks to a pre-programmed chip and tells it what it should do). In the first case, couldn't one use any old PIC programmer instead of spending $100 on yours?

author: Stathera
author_rank: Newbie
timestamp: September 27, 2020, 03:11:32 am
content: Hi,Thanks for the feedback!Yes, you can use an off-the-shelf PIC chip in the programmer. Sorry if it is not clear. I'll try to fix that.You can also change the parameters in-circuit by connecting the programmer to a header. That is not clear in my description. I'll work on that.Thanks again.

author: PlainName
author_rank: Super Contributor
timestamp: September 27, 2020, 04:08:22 am
content: OK, thanks for clearing that up.Ummm... so what's to stop someone using a different programmer? Is your application locked to yours?

author: Stathera
author_rank: Newbie
timestamp: September 28, 2020, 02:57:48 am
content: Thanks for that question. It's a good idea but there are two problems with doing this.1) Other programmers (e.g. PICKIT3 is popular) don't give you an API or document their interface (that I know about) so no way to implement.2) The PULS programmer does more than just program the PIC chip. It also calibrates the internal oscillator and registers of the PIC chip. It has a somewhat sophisticated algorithm to do that. I don't think I can implement it using someone else's programmer.Thanks!

author: PlainName
author_rank: Super Contributor
timestamp: September 28, 2020, 03:43:43 am
content: OK. Could be worth mentioning that as a reason to acquire your programmer. Apologies in advance if you already did and I missed it!