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reviving the BASIC stamp

 by viskr ¦  Sat Nov 11, 2017 10:22 pm ¦  Forum: New Product Ideas ¦  Topic: reviving the BASIC stamp ¦  Replies: 0 ¦  Views: 757

I've got a Kickstarter project going (and now funded) to bring new components to the old Parallax BASIC stamp. It was a good product in its day 20 some years ago, but was a dead end. I propose adding a USB embedded ARM in the same form factor and pin out and bringing that to market as an open source...

Re: flash memory option for ARM

 by viskr ¦  Mon Dec 01, 2014 5:23 pm ¦  Forum: Everything ARM and LPC ¦  Topic: flash memory option for ARM ¦  Replies: 2 ¦  Views: 2013

I'll second Steve's suggestion. The questions you need to consider are- How much data changes and how much has to be written when power goes away? Or is it something you are posting as the program is running. You may not have enough time to write to a Flash style memory if you have limited warning o...

Re: LED and Push button problems in LPC 2119

 by viskr ¦  Mon Nov 24, 2014 1:44 pm ¦  Forum: Everything ARM and LPC ¦  Topic: LED and Push button problems in LPC 2119 ¦  Replies: 13 ¦  Views: 4221

The LPC2148 is a superset of the LPC2138, which we have a set of gcc tools configured for. If you don't have a JTAG connection or debugger, you should include a small monitor into your C program, something we routinely do. Yes this is kind of old school, but it lets you read and write memory locatio...

Re: LED and Push button problems in LPC 2119

 by viskr ¦  Wed Nov 19, 2014 5:18 pm ¦  Forum: Everything ARM and LPC ¦  Topic: LED and Push button problems in LPC 2119 ¦  Replies: 13 ¦  Views: 4221

I can assure you IOSET and IOCLR work on the LPC2119. The part has been shipping for probably 10 years, and millions in the field So ignore the button issue, you should be able to set a pin high with IOSET is a simple program. If you can't then you have a define wrong or something similar. If you ar...

Re: LED and Push button problems in LPC 2119

 by viskr ¦  Wed Nov 19, 2014 6:31 am ¦  Forum: Everything ARM and LPC ¦  Topic: LED and Push button problems in LPC 2119 ¦  Replies: 13 ¦  Views: 4221

Switches bounce which means they dont go from 0 to 1 once per switch, but can do it many times before settling. Does your code expect that?

Re: LED and Push button problems in LPC 2119

 by viskr ¦  Tue Nov 18, 2014 5:29 pm ¦  Forum: Everything ARM and LPC ¦  Topic: LED and Push button problems in LPC 2119 ¦  Replies: 13 ¦  Views: 4221

Are you sure you want to do a IOSET1 |=(1<<16); The purpose of the set/clear registers it to write a 1 to bits you want to SET/CLEAR and leave the rest alone. Typically I never do |= operations on those registers. As in some NXP ARMs reading the SET register will return the pin state, some NXP ARMs ...

Re: Transistors to drive LEDs

 by viskr ¦  Sun Aug 03, 2014 5:08 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Transistors to drive LEDs ¦  Replies: 2 ¦  Views: 2126

When you are driving LEDs or loads that are typically on or off, you just want to saturate the transistor. As to why they chose the PN2369, you would have to ask the author as it is not very common. A more common choice would be a 2N2222 which is made by everyone and can be found lots of places incl...

Re: Help with dual rail power supply

 by viskr ¦  Thu Oct 31, 2013 11:36 am ¦  Forum: Projects ¦  Topic: Help with dual rail power supply ¦  Replies: 3 ¦  Views: 1183

As you've got an ICL7660, I'd go with that to generate the -12V. The V4580L will operate up to +/-15V supplies. Just make sure your 12V supply really is 12V and not a lot more (which it might be if it is just a cheap linear walwort). In any case you will have to filter the switching noise from the s...

Re: Is this possible?

 by viskr ¦  Mon Oct 14, 2013 7:09 pm ¦  Forum: Projects ¦  Topic: Is this possible? ¦  Replies: 1 ¦  Views: 394

Yes this is quite do-able. Actually would be a pretty good first project for someone. Start with a red board, https://www.sparkfun.com/products/11575 Add an LCD, https://www.sparkfun.com/products/11851 And write some software. The question then is, do you need it to be on when the PC is off, that me...

Re: STM32 maximum GPIO speed?

 by viskr ¦  Wed Sep 11, 2013 6:02 pm ¦  Forum: Everything ARM and LPC ¦  Topic: STM32 maximum GPIO speed? ¦  Replies: 4 ¦  Views: 6930

The LPC2148 is going on 8 years old now, so there are faster parts in NXPs quiver.

The LPC43xx line has clock rates of 204 MHz and the FIOs will probably toggle 3x the LPC2148. It also has a SerialGPIO that is a bank of configurable shift registers that run up to the 204 MHz rate.

Re: RTC with Supercapacitor Recharge

 by viskr ¦  Wed Sep 04, 2013 7:50 am ¦  Forum: SparkFun Product Questions ¦  Topic: RTC with Supercapacitor Recharge ¦  Replies: 40 ¦  Views: 10992

Just FYI From my experience most PCs will limit current to 500 mA, some even limit it more, as according to the USB spec the device is suppose to consume less than 100 mA unless it requests more from the host. Most USB hubs don't care what kind of power you try to suck out of them. I use an older De...

Re: What is the best ARM solution for new project?

 by viskr ¦  Wed Aug 21, 2013 1:57 pm ¦  Forum: SparkFun Product Questions ¦  Topic: What is the best ARM solution for new project? ¦  Replies: 1 ¦  Views: 401

The current part I like is in the LPC43xx family from NXP, dual core, 200 MHz Won't have 4 SPIs, not sure I've seen that anywhere, but usually you just use 1 SPI and multiple SSEL Not sure you'll get all 8 PWMs, but 4 and probably 6 can be done in that part I haven't seen 2 DACs on any micro, that j...

Re: Smart Camera

 by viskr ¦  Wed Aug 21, 2013 8:15 am ¦  Forum: SparkFun Product Questions ¦  Topic: Smart Camera ¦  Replies: 8 ¦  Views: 1127

This looks like what the doctor ordered

http://www.kickstarter.com/projects/254 ... ion-sensor

I've used the multi-core 200+ MHz LPC4330, truly an impressive performing part for less than $10 even in small quantities.

Re: Estimated duration with battery

 by viskr ¦  Wed Aug 21, 2013 7:18 am ¦  Forum: Arduino ¦  Topic: Estimated duration with battery ¦  Replies: 2 ¦  Views: 597

The current draw is not 0 when in standby mode for any microprocessor. So you have to add that into the total, and the lower that is the longer you will have. That mode can vary widely depending on what peripherals are running. This is where all the vendors are competing to get that power down mode ...

Re: Arduino sampling speed

 by viskr ¦  Mon Aug 19, 2013 6:41 pm ¦  Forum: Arduino ¦  Topic: Arduino sampling speed ¦  Replies: 8 ¦  Views: 1542

You might want to consider a different CPU, many ARMs give you much faster A/Ds, with conversion times of 2.5 to 5 microseconds. The multiple AD inputs still share the same converter, but they can also be tied to a DMA channel such that the conversions will always occur x microseconds apart, so with...

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