6 years, 8 months ago.

9 bits mode supported in SPI interface ?

Hi there,

I just want to make sure that this board can support 9 bits SPI mode or not. There is a Nokia 6100 LCD shield that uses 9 bits mode. Does it fit in with this board?

Question relating to:

The FRDM-KL46Z is an ultra-low-cost development platform enabled by the Kinetis L series KL4x MCU family built on the ARM® Cortex™-M0+ processor. Features include easy access to MCU I/O, battery-ready, …

2 Answers

6 years, 8 months ago.

No, the SPI can only support 8 or 16-bit mode on the KL46Z. Of course you can use software SPI, although that is not as handy as hardware SPI. (For example: http://mbed.org/users/davervw/code/SWSPI/)

Accepted Answer

Hi Erik,

Thanks again!

I will give it a try with the software SPI.

posted by JP PANG 13 Feb 2014
6 years, 8 months ago.

Hi Erik,

I have tried the SWSPI lib, and though I can compile my code, the LCD did not work. The error message output to PC via serial port is : "Only 8/16 bits".

Here is my code:

SWSPI and NokiaLCD

#include "mbed.h"
#include "NokiaLCD.h"
#include "SWSPI.h"

SWSPI swspi(D11, D12, D13);
NokiaLCD lcd6100(D11, D13, D9, D8, NokiaLCD::LCD6100);
DigitalOut led(LED2);

int main() {
    swspi.format(9, 0);
    while(1) {
        led = 1;
        led = 0;
        printf("this is a test. \n\r");
        lcd6100.printf("this is a test \n\r");

Where did I go wrong?

How to bind SWSPI with NokiaLCD together?

You aren't actually using the SWSPI. In the NokiaLCD library it makes an SPI class (at least I assume it does). You need to replace that one by SWSPI, now it still uses the regular SPI there, and it gives the error that it only supports the 8/16-bit of the KL46z hardware SPI.

posted by Erik - 17 Feb 2014

Hi Erik,

You means I have to rewrite the NokiaLCD class, that's right? OK, I will figure out how to do that.

Thanks for your advice.


posted by JP PANG 17 Feb 2014

Hi Erik,

I have rewritten the orginal NokiaLCD lib by using the SWSPI lib. It works!

Finally, I can play with this LCD shield on KL25Z and KL46Z boards.

Here is the link to my code.

Import programKL46Z_NokiaLCD

Rewrite the NokiaLCD lib by using the SWSPI lib in order to fit in with the 9 bits SPI mode of KL46Z.

Thanks again.

posted by JP PANG 18 Feb 2014