LPC2101 Development Board JTAG Debugger EAGLE Part Library lpc2103.h WinARM Toolchain Documentation LPC2101 Datasheet Full User's Manual Technical Docs Tips, Tricks, and Traps FAQ Insider's Guide to LPC21xx Digi-Key Part Click to join lpc2000

LPC2101 Features

• Low priced at $1.96 in 100 unit qty. from Digi-Key.
• Up to 70MHz (63MIPS) 32bit ARM7TDMI-S core.
• 3.3V I/O (5V tolerant). 1.8V core
• 2 UART, 2 I2C, 1 SPI + 1 SPI/SSP
• 8 channel, 10-bit ADC
• 4 PWM counters
• 8KB FLASH / 2KB SRAM
• 7mm x 7mm LQFP with 0.5mm lead spacing

News

03-22-2007

Finally ordered a PCB of the K9JTAG board. Soldered it all together and successfully connected using OCDRemote. Haven't soldered down the low pass filtering capacitors yet. Also haven't soldered down the circuitry for external power.

Added pre-assembled BBMICRO Development Boards available for ordering. Finished soldering some last night, and shipped our first two this morning (pre-ordered).

Added bare LPC2103 chips available for ordering. As soon as I have a few more BBMICRO's done, we'll make those available too.

Spent many hours soldering BBMICRO Development Boards this weekend. Only got one additional completed board done. Three more are almost half way done, and another three just have the LPC2103 chip soldered down. I've been doing these with the water soluable flux, which makes them much prettier looking in the end than the first board I soldered. The downside is that it takes longer to finish a board this way, since there are added washing/drying steps.

Also spent some time soldering more components onto the vectorboarded K9JTAG prototype. Still a few more parts left to go. It's really slow building a circuit without a printed circuit board.

Looks like we're going to be set up for a busy weekend. The Mouser resistors are definitely going to be delivered to us tomorrow, and the LPC2103 chips are currently on-time for a Friday delivery.

Submitted an order for some more LPC2103 chips and hopefully the backordered resistors from Mouser will ship tomorrow. If it all arrives before this weekend, I'll be busy all weekend soldering up some pre-assembled BBMICRO's.

Posted an updated K9JTAG Debugger schematic diagram. This schematic should match the 10 pin JTAG header on the BBMICRO Development Board. I also finally started building my first K9JTAG by hand on a perfboard, but I can't finish it yet because we're still waiting on some more resistors from Mouser.

Also updated the lpc2103.h include file with some more register definitions. I'm not 100% sure, but this might be complete now.

Posted an initial lpc2103.h include file under GNU GPL. It's still missing some registers, but it's got a lot of the most important ones to start with.

The board works! I've got blinking LED firmware uploaded and running! I haven't tried using the JTAG pins yet, but so far so good.

Plugged power into the first BBMICRO, hooked up the serial port, and hit the "Read Device ID" button in the Philips Flash Utility. It successfully read the device ID as LPC2103/2/1, Part ID 327441, Boot Loader ID 2.2! Now I gotta try writing up some firmware to blink an LED.

Most of the parts arrived yesterday, and the boards arrived today. Soldered one together tonight, but I don't have time to try it out because I have to go to work tomorrow. Doh! At least I was able to test the voltage regulators before soldering down the LPC2103 chip. I got +3.3VDC and +1.94VDC, just like it should. So that's pretty good, and everything else physically fits okay, which is also quite good.

The LPC2103 chip was definitely more difficult to solder than my other boards. Three sides of it started off with solder bridges all over the place. One side I got through without making any solder bridges at all somehow... Hopefully that side actually got enough solder. I fixed all the solder bridges by putting down more flux, and then used the soldering iron to sweep the excess solder away to surrounding pads. I'll do some continuity checking with my meter tomorrow to make sure I really did fix them all.

Started putting together a website for the upcoming BBMICRO Protoboard. Spent the weekend putting together a parts list for it. Ordered over $200 worth of parts from Mouser to add to the parts I've already got in stock for building the first BBMICRO. Hopefully everything will arrive before next weekend so that I can spend next weekend assembling one and testing everything out.

I haven't ordered the K9JTAG debugger board yet. It uses the same 1.3mm DC power jack that the BBMICRO uses, and I want to make sure the parts actually fit on the BBMICRO before wasting more money on additional boards. Once we have BBMICRO boards back, I can verify it works and then submit an order for the K9JTAG boards.

Stayed up really late last night and submitted the LPC2103/2/1 protoboard (BBMICRO) for manufacture. Ordered 100 boards from Advanced Circuits and should arrive in a week or two. I hope this board works correctly, I'm kind of going out on the limb here on the 100 unit qty. I'll need to work on getting my components ordered from Mouser/Digikey next.

I've got the K9JTAG debugger schematic fixed to match the protoboard JTAG header pinout (haven't updated the website copy yet though). I also have the board fully routed. I need to print both of these boards out and do a parts fit verification test. I might want to make a couple more board layouts before submitting for manufacture though. Since BatchPCB.com requires a $10 set up fee now, it is better to run a bunch of boards all at once, instead of ordering them separately. I'm thinking of maybe making development boards for the SD Card socket, 3.5mm audio jack, and Nokia LCD screen interface.

Posted the latest protoboard schematic diagram. This is the one that includes voltage regulators for the 3.3V and 1.95V rails. Yesterday we soldered a SOT-223 FAN1117ASX regulator to a small PCB and plugged it into a bread board for some testing. It looks like we can use it for providing the 1.95V (or whatever voltage we end up at) for the LPC210x chip. I was a worried about the 10mA minimum load current in the datasheet, and still am a little bit, but it seemed to work okay without load in the bread board as long as we had an output capacitor.

I've got the protoboard layout fully routed with both regulators now. Next I'm going to work on updating the K9JTAG Debugger Board to match the pin out of the protoboard JTAG header and try to route it.

Spent the weekend doing some more work on the LPC2101/2/3 Protoboard. After printing out the mock PCB, it was appearant that the DB9 connector wasn't sticking out far enough to rest off the edge of the bread board. So, I moved it outward, expanding the board length a bit. After that, I had some extra board space, so I started adding some jumpers for DBG/ISP, added a button for RESET, added a DC power jack, and a 3.3V linear regulator.

I also found some bugs. The MOSFET circuits for driving P0.14 and RESET low from the PC's serial port weren't going to work. I ended up replacing them with some of the unused 7414 gates. One thing still remaining is that the JTAG port might not work as well as the 20 pin JTAG header standard used on other LPC2100 development boards. I'm only using a 10 pin header for JTAG, to reduce board space. This means I don't have as many GND pins separating adjacent signals though. I'm currently thinking maybe I should swap TRST and TDO pins on the JTAG header. Then I'll have both optional TRST and RTCK on one side of the header together with the two GND and +3.3V signals. Since TRST and RTCK are optional JTAG signals, in a pinch I could cut the traces to the header and solder bridge the GND signal across those pins. This would then place GND signals in between all high speed data signals in the JTAG ribbon cable, just like the 20 pin standard.

Posted a copy of the LPC2101/2/3 Protoboard Schematic Diagram. We haven't built this circuit yet, there may be bugs. If you see any, please let us know!

Spent the last two weekends routing an LPC2101/2/3 LQFP-48 to DIP break-out board. I've finally got everything pretty much routed. Now I just need to do a little optimizing and then double check that everything is right before I send it off for PCB manufacture.

This break out board is pretty cool. The board size is less than 2 inches square, so it should not cost too much to make a large pile of them for others. It has a DB9 serial port connector on one end and a JTAG in-circuit debugger header on the other end. The serial port connector should allow you to FLASH program the chip in-circuit without any extra programming circuit. The two outer edges have pin headers that will interface easily with a bread board, as if it were a 44 pin DIP chip.

The board integrates the 32.768KHz real time clock, core processor clock, and 0.1µF power decoupling capacitors. You still have to provide +3.3VDC and +1.8VDC regulated power supplies off board though. I didn't integrate that in because the errata sheet says something about needing to possibly provide 1.95VDC when running all the peripherals and core processor at maximum speed.

Ran some print outs and updated my ARM EAGLE Part Library so that the pads of the LQFP-48 will work better. Previously, I had just cut and pasted the standard EAGLE PQFP-48 SMD layout. Here is what I changed:


• The pads are now 0.27mm wide, which is the maximum specified width of the LPC2101 pins, according to the datasheet. This makes the space between pads a bit wider, which is more important in my opinion. I want to avoid unwanted bridging of pins when etching boards and soldering pins; having extra wide pads isn't as important for me.
  
  
• The pads are moved outwards a little so that more of the pad is exposed outside of the chip for hand soldering. Previously, a huge amount of each pad was underneath the chip itself, with a good portion not even under the pins at all (under the plastic instead). This will make it possible to maybe route one trace diagonally out from underneath the chip in each corner, where before it would be impossible.
  
  
• Made all of the power pins separate invokable pins instead of having them all on the main device block (for the schematic layout). Also rearranged some of the pins on the main block into functional units instead of just straight pin number order.

My LPC2103 order arrived today. Don't have time to open it up and check my EAGLE Part Library against the real chip, but will hopefully get to do so this weekend.

Added a screen shot of my current protoboard design above. I'm not quite happy with the layout on this one yet. I'm currently debating flipping the SD Card socket back around to the top side and maybe putting the LPC210x chip on the bottom side. I need to make the bottom side as flat as possible to provide space for batteries.

Updated the JTAG Debugger schematic to include support for driving the TRST signal from the parallel port's DATA4 signal. My understanding of ARM Application Note 31 is that TRST must be pulsed low to reset the TAP controller of the chip so that JTAG debugging can work reliably.

Drew a schematic for a simple parallel port JTAG Debugger circuit that I'll need to do in-circuit debugging of my LPC2103 circuits. Not tested yet, but should work.

Threw together an EAGLE part library for the LPC2101/LPC2102/LPC2103 LQFP-48 chips.

Ordered samples of the LPC2103 chip.