interesting little chip

[fixstuff]

Anyone look at an LPC810M21FN8? I recently bought a couple of these after seeing a couple of articles on them, and I must say I find them very interesting. They are basically an 8pin DIP version of an 30MHZ 32bit Arm Cortex M0 processor core. NXP's whole push on this chip is to use it as a replacement for small 8bit and 16bit applications.

There are several neat features of this little guy.

One, is the 8 pin DIP package. Its nice just being able to breadboard this up really easily. I love through hole devices, especially for prototyping.

Two, it requires hardly any cost in getting set up. I had an old USB to TTL serial converter, that and a couple breadboard wires is all you need to program and run this little guy. Spent $10 for 10 of these.

Three, the software is all free to download. NXP offers the LPCXpresso for free download.

Four, is the switch matrix in the chip. Basically any internal feature can be mapped to any pin other than Vcc and GND. It comes with 2 USARTS, 2 SPI, and 1 I2C ports, a comparator, and an SCT (something called a state-configurable-timer).

Five, it has a few nifty little power features such as wake on I2C, needs no external components, etc.

Heres a link: http://www.nxp.com/products/microcon...10M021FN8.html

Here's my thoughts. Even though it only has 4kb flash and 1kb sram, you could use this chip as a building block. Test and debug each little feature needed in a MD, tie them all together with perhaps I2C, and have a supervisor chip run the whole process... Just thought it was a cool little chip.

Would there be any interest out there for a metal detector running using a handful of these?

[sinclairuser]

just looked at the page, you are right a very interesting chip.

[Silver Dollar]

The problem is that 8 pins isn't much to work with. I've used the majority of pins
on the 18F4550 in adding features. There's no A to D but you could add one with
SPI but then need a second SPI to talk to another chip. Is there enough pins to
do a second SPI?

[greylourie]

Hi fixstuff,

One idea would be to use these for an TX and auto-damping solution. I can think of a few of the P.I projects here that could benefit , and give the user the opportunity to expand their range of coils without being constrained by fixed damping. Or even as a replacement for the 4 off 4538's in the Goldscan, in fact it could make up a timer block for use with any of the projects here.

Nice find and good thinking.

[fixstuff]

Yeah, I don't think it could do everything itself either - not enough pins for sure.

If used as a generic building block however, it could potentially replace a whole host of auxiliary functions that normally right now take up resources.

You could use it to eliminate wiring normally needed to just a few between the master controller and the sub-controller - more or less a distributed control architecture.

Another very interesting concept with these could be programmability at boot up. Since the chip is programmed so easily, you could theoretically program all of the sub-controllers from the master at boot up. This would be the ultimate in customizable hardware, without having to reprogram all of the sub-controllers.

Here are some right off the top that I can think of.

1) keypad / encoder decoder controller. Read a I2C port expander chip or 2 with switches and an quadrature encoder (override knob), with SPI interface back to master supervisor processor. House this on keypad itself, only a couple wires to master supervisor control board.

2) Transmit coil controller. Run a H-bridge directly from this chip to perhaps a couple PSMN070-200P N-channel FETs. Run this right on the coil, interface back to supervisor up MD stem over SPI bus.

3) Received data controller. Read an I2C port with a high speed A/D, 16bit or higher. Sample the A/D as fast as possible, not worry about timing, blast the reading back to the supervisory controller over SPI. Could house this on or near coil also.

4) LCD controller. Read messaging from supervisor over SPI bus to LCD text display screen.

5) Switched Mode PS controller. Run another H bridge to controller the power regulator section, tie SPI channel to supervisory processor. Run right on a power supply board.

6) Raw Receiver / Demod Controller. Dedicate chip to interface to pre-amp and sampling circuit for controllable gain, sample times, etc. over I2C. Interfaced back to master supervisor over SPI.

7) Audio controller. Over I2C control a MP3 playback chip with predefined samples for many different materials. Communicate back to master over SPI or to wireless controller.

GPS Controller. Read and decode a GPS reciever over I2C, send results back to supervisor controller.

9) Accelerometer / Gyroscope controller. Read and decode accelerometer and gyroscope chip over I2C, send back to master supervisor of SPI. You could potentially work out some nifty feedback controls based on the position, and speed of the detector. Perhaps tell the user the swing speed is ok or something.

10) Data logger controller. interface to SD card over I2C, and interface to master supervisor over SPI. Perhaps log GPS and target readings with timestamp to the card.

11) Wireless Transmit controller. Using XBEE or similar, controlled over I2C, and interfaced to master supervisor over SPI and transmit wireless data to Wireless Receive Controller.

10) Wireless Receive controller. Same as above, except interfaced to Audio controller.

I'm sure there are plenty other ideas that these could fit under. The key is to break out code into its simple constituent components and locate them at the feature, rather having all of that in one processor. Each "piece" could get debugged and finished up, without hurting the big picture. Even the sub-controller boards (if separate) would be way simpler, and could be interchangeable in different MD designs.

[Silver Dollar]

The ATiny25 has 8 pins and a 10 bit ADC. 20 mhz ~ 20 MIPs

http://www.atmel.com/devices/attiny25.aspx

[Waikiki_Sweep]

The ATiny25 has 8 pins and a 10 bit ADC. 20 mhz ~ 20 MIPs

http://www.atmel.com/devices/attiny25.aspx

And ATiny85 which is the same as ATiny25 but has flash 8 Kbytes. And they are cheap!

[fixstuff]

Yeah, but the LPC810 is a 32 bit chip, has I2C and SPI ports built into the chip, and can be assigned to any pin via the switch matrix.

It has a single cycle 32 bit multiply, and single cycle IO. Based on the chart, I'd rather have the LPC.

In addition, it doesn't require any programmer, its cheaper (digikey $1.37 versus $1.53).

In all fairness to the ATiny's, this chip is intended to replace those older chips and be faster/better/cheaper doing so.