MPR121 Autoconfiguration

markthedark — Tue, 09 Oct 2012 16:04:59 GMT

I have some questions about the MPR121 Touch Sensor Auto configuration sequence that is not explained well in the Reference Manual or Application Notes.

1. What is the purpose of the Target Level register?

2. How can I tell when the Auto-complete sequence is complete?

3. Is there source code or a flow chart of how the Auto-complete should be coded?

Thanks in advance.

Re: MPR121 Autoconfiguration

Joshevelle — Tue, 16 Oct 2012 18:10:26 GMT

Hello Mark,

I noticed that you entered SR#1-948472563 for this inquiry and we already sent you a response.

However, I thought that the suggested initialization code might be useful for you:

#define TouchThre 10 //15//30//10

#define ReleaThre 6 //8//25//8

void MPR121_init(void)

{

//Reset MPR121 if not reset correctly

IIC_ByteWrite(0x80,0x63); //Soft reset

IIC_ByteWrite(0x5E,0x00); //Stop mode

//touch pad baseline filter

//rising

IIC_ByteWrite(0x2B,0x01); // MAX HALF DELTA Rising

IIC_ByteWrite(0x2C,0x01); // NOISE HALF DELTA Rising

IIC_ByteWrite(0x2D,0x0E); // NOISE COUNT LIMIT Rising

IIC_ByteWrite(0x2E,0x00); // DELAY LIMIT Rising

//falling

IIC_ByteWrite(0x2F,0x01); // MAX HALF DELTA Falling

IIC_ByteWrite(0x30,0x05); // NOISE HALF DELTA Falling

IIC_ByteWrite(0x31,0x01); // NOISE COUNT LIMIT Falling

IIC_ByteWrite(0x32,0x00); // DELAY LIMIT Falling

//touched

IIC_ByteWrite(0x33,0x00); // Noise half delta touched

IIC_ByteWrite(0x34,0x00); // Noise counts touched

IIC_ByteWrite(0x35,0x00); // Filter delay touched

//Touch pad threshold

IIC_ByteWrite(0x41,TouchThre); // ELE0 TOUCH THRESHOLD

IIC_ByteWrite(0x42,ReleaThre); // ELE0 RELEASE THRESHOLD

IIC_ByteWrite(0x43,TouchThre); // ELE1 TOUCH THRESHOLD

IIC_ByteWrite(0x44,ReleaThre); // ELE1 RELEASE THRESHOLD

IIC_ByteWrite(0x45,TouchThre); // ELE2 TOUCH THRESHOLD

IIC_ByteWrite(0x46,ReleaThre); // ELE2 RELEASE THRESHOLD

IIC_ByteWrite(0x47,TouchThre); // ELE3 TOUCH THRESHOLD

IIC_ByteWrite(0x48,ReleaThre); // ELE3 RELEASE THRESHOLD

IIC_ByteWrite(0x49,TouchThre); // ELE4 TOUCH THRESHOLD

IIC_ByteWrite(0x4A,ReleaThre); // ELE4 RELEASE THRESHOLD

IIC_ByteWrite(0x4B,TouchThre); // ELE5 TOUCH THRESHOLD

IIC_ByteWrite(0x4C,ReleaThre); // ELE5 RELEASE THRESHOLD

IIC_ByteWrite(0x4D,TouchThre); // ELE6 TOUCH THRESHOLD

IIC_ByteWrite(0x4E,ReleaThre); // ELE6 RELEASE THRESHOLD

IIC_ByteWrite(0x4F,TouchThre); // ELE7 TOUCH THRESHOLD

IIC_ByteWrite(0x50,ReleaThre); // ELE7 RELEASE THRESHOLD

IIC_ByteWrite(0x51,TouchThre); // ELE8 TOUCH THRESHOLD

IIC_ByteWrite(0x52,ReleaThre); // ELE8 RELEASE THRESHOLD

IIC_ByteWrite(0x53,TouchThre); // ELE9 TOUCH THRESHOLD

IIC_ByteWrite(0x54,ReleaThre); // ELE9 RELEASE THRESHOLD

IIC_ByteWrite(0x55,TouchThre); // ELE10 TOUCH THRESHOLD

IIC_ByteWrite(0x56,ReleaThre); // ELE10 RELEASE THRESHOLD

IIC_ByteWrite(0x57,TouchThre); // ELE11 TOUCH THRESHOLD

IIC_ByteWrite(0x58,ReleaThre); // ELE11 RELEASE THRESHOLD

//touch /release debounce

IIC_ByteWrite(0x5B,0x00);

// response time = SFI(10) X ESI(8ms) = 80ms

IIC_ByteWrite(0x5D,0x13);

//FFI=18

IIC_ByteWrite(0x5C,0x80);

//Auto configuration

IIC_ByteWrite(0x7B,0x8F);

// charge to 70% of Vdd , high sensitivity

IIC_ByteWrite(0x7D,0xE4);

IIC_ByteWrite(0x7E,0x94);

IIC_ByteWrite(0x7F,0xCD);

// 12 electrodes enabled

IIC_ByteWrite(0x5E,0xCC);

}

...hope it helps! =)

Josh

Re: MPR121 Autoconfiguration

Janosch — Mon, 05 May 2014 21:49:43 GMT

Hello,

i would be still very interested in #2 of the original question:

Mark Donkers schrieb:

2. How can I tell when the Auto-complete sequence is complete?

Is there any way to determine, or at least to take a good guess, when the auto-calibration of the sensor is completed?

Thanks

Janos

topic Re: MPR121 Autoconfiguration in Sensors

MPR121 Autoconfiguration

Re: MPR121 Autoconfiguration

Re: MPR121 Autoconfiguration