What did you do to get MBED to compile for LPC812 ?
I cannot get the compiler to work for my shiny new LPC-800-MAX board :(

Cheers

Ceri

Hi Ceri, did you add the lpc device to your set of devices. Click on device select button (top right) in compiler window, then if needed first add and then select the lpc max. The first time you compile the source you may want to select 'compile all' from the compile drop down list. Thats it. Should compile now. Use P0_xx. Note that LED on max will light when pin is set to 0.

Just a bit of code to show Port Expanded ADC working:

#include "mbed.h"
 
DigitalOut myled1(LED1);
DigitalOut myled2(LED2);
 
// Host PC Communication channels
//Serial pc(USBTX, USBRX); // tx, rx ===> Note default Pinnames USBTX and USBRX are wrong for LPCXpresso LPC812 !
Serial pc(P0_4, P0_0); // tx, rx

I2C i2c(P0_10, P0_11);
 
int main() {
    pc.printf("Hello World from LPC812\r\n");
    
       char data[1],vdata[2];
       float a,b;
       data[0]=0x02;        //selecting AIN2 for PCF 8591 //
       i2c.start();
       
       i2c.write(0x90 | 0x0e,data,1);
       
       
           
    while(1) {
        myled1 = 0;
        wait(0.1);      
        myled1 = 1;
        wait(0.1); 
        
        myled1 = 0;
        wait(0.1);      
        myled1 = 1;
        wait(0.1);         

        myled2 = 0;       
        wait(0.1);
        myled2 = 1;               
        wait(0.1);  
                
        myled2 = 0;       
        wait(0.1);
        myled2 = 1;               
        wait(0.5);
        
    {
            i2c.read(0x9e,vdata,1);
            wait(0.3);
            b=vdata[0];
            a=(b/256) * 3.3;
            pc.printf(" the voltage is %f ",a);
    }        
        
        pc.printf("\r\n");        
    }
}

updated from: https://mbed.org/forum/mbed/topic/4269/

Enjoy

Ceri

Hi Ceri, I am developing a class for the PCF8591 at the moment. It is working fine on the LPC1768 but shows intermittent errors on the LPC812. It looks like a problem with the LPC812 I2C libs, but need to investigate further. I will publish as soon as the problem is sorted. Im running tests on the LPC812 LPCXpresso while awaiting delivery of an LPC800 MAX board.

EDIT: problem with the PCF8591 has been fixed. See here for the lib.

Sounds good,

I wonder if there is a 10 or 12 bit version ??

Ceri

The pcf8591 design is at least 25 years old! Newer devices offer more channels and higher resolution. Examples are ad7995 (4x 10 bit), ad7992 (2x 12 bit). Dont know any that include ADC and DAC. However, you can use separate converters on the same i2c bus.

Hi Wim,

I just got my LPCXpresso LPC812 [rev B] working with ISP (using the excellent free (GPL) software lpc21isp v1.93).

It did not work at first, due to a design-fault: the ISP RX node [P0_0] is also connected on the Xpresso to the "Trimming Pot". If the Pot is at one end, or the other, the ISP_RX is crushed with a 220 ohm resistor!

With my FTDI cable, the Pot has to be set to about mid-way to allow the ISP to function OK.

Also, with the ISP connector J7, the Cable you use must be checked: the supply-out from the cable must be 3.3V - or else remove pin 3 (and power the board from external power supply).

I also noticed the issue with the Trimming pot and used series resistors (330ohm) for TX and RX to the FTDI cable. That works fine. You cant see them in the pic above: they are hidden underneath the LPC812 board. I also use series resistors for the SWD programmer (visible in the pic) to add some protection to the LPC812 portpins.

The LPCXpresso board has no onboard voltage regulator. You should supply 3V3. In my setup I use an FTDI that provides 5V supply and feed that to a regulator. Note that newer FTDI cables are available that provide 3V3 rather than 5V. Some offer a jumper or switch to select the voltage.

Hi Wim, have you seen a schematic for the rev B LPCXpresso LPC812 ?

The rev B is changed to follow the change of ISP-enable pin (from P0_1 to P0_12 on LPC812 TSOP/SOP chips marked 4C & later). Sadly, the rev B does not fix the flaw with the trimmer pot. I don't know if there are more hazards like this.

Yes, I have seen the rev B schematic. Looks like the ISP pin is the only change. However, both my LPCXpresso board and my LPC800 MAX board have the first revision LPC812 devices.

I have been considering to modify the LPCXpresso somewhat to align it more with the LPC800 MAX. The changes would include: removing the X-tal bridges and let the LPCXpresso use the internal oscillator (freeing up pins P0_8 and P0_9 and wiring these to the external headers), add a 3V3 voltage regulator on the LPCXpresso small experimentation area. The board would accept 5V input on Vin pin2 and provide 3V3 out on pin 28 (which is the same as mbed pin40).

Can I use the LPC link to program other LPC mcu if ever I want to make my stand alone board?

Hi Felan, the LPC link part of the LPCXpresso board is really just a SWD programmer. It can be used with other LPC processors on your own boards. However, the LPC link uses a special driver on the PC side that only works with the LPCXpresso toolset as far as I know. You would probably be better of with a generic JTAG/SWD programmer like Segger J-Link or use one of the mbed programmers like the one on the LPC812 MAX board (find the example page on mbed). Note that you can still use the mbed online compiler to flash any of the supported LPC devices using a tool like J-Link.

I use the LPC Link, mostly because I have it around and I already use the LPCxpresso IDE, without any issues. There is a toolbar button that is used to flash a chip with an already compiled binary file like one you get from the MBED online compiler.

Just make sure you design the board so you have access to the SWD pins.

You can also look into UART0 ISP bootloading which uses less hardware and pins. The downside is there is no debugging capability even with the LPCxpresso IDE.

The mbed programmer was spot on! It was what I really wanted to ask and do in the first place :D I think i'm going to have to invest on a Segger J-link as I'm also experimenting with Freescale's kinetis mcu. Thank you for your response! :D

Hai

I am working on lpc-812.I have build the code no errors and i have started debug there i got the error.The error is

Failed on connect: Ep(01). Target marked as not debuggable. Conn&Reset. Was: None. DpID: BC11477. Info: HID64HS12 can any one help on this error.

From my experience this is a general error when the micro has trouble or is completely unable to communicate using LPC Link (probably any debugger).

I have seen this when - The SWD wires were not hooked up correctly - The LPC812 was not powered. The debugger might not supply power depending on the board or design. - The SWD pins are not setup correctly. I try to use the default SWD pins just in case. - Other circuits caused the micro not to function correctly.

Are you using this on your own LPC board design, LPCXpresso or the LPC800-Max? It would help if we knew what board you are using.

Hope this helps.

I am using LPC-812 in LPCXpresso.I am not able to understand what is the problem Exactly.

I am using LPC-812 in LPCXpresso along with the IDE. I too see the same error which Vijay reports. I connected the UART TX and RX pins of the LPC-812 to the host PC running the IDE. When the IDE was reflashing my code, I temporarily grounded the ISP pin on the LPC-812. Then, the error was gone and code runs properly.

But, some time later during next flashing of the code, I see this error again. Is there some way this could be controlled from the IDE?

Thanks in anticipation, Niranjan

The lpc812 is programmed and debugged using its SWD port. The SWD portpins may also be used as regular portpins when you remap them through the switchmatrix. That may lead to disabling of the program and debug functions. Only a hard reset to ISP mode at poweron can re-enable the SWD functionality. Are you using the SWD pins for anything else? Are you using the switchmatrix at all? I have seen forum reports that there were bugs in some lpcxpresso code examples that used the switchmatrix and unintentionally disabled the SWD pins. Checkout the lpcxpresso forum for lpc800 and/or lpc812 .