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Quadrature Decoder - select appropriate type

3 months ago

Quadrature Decoder - select appropriate type

Posted byadam.stroz35 points 7 replies
0 upvotes

Hello,

I have a small questions about using rotary encoder with DA14531.

How to choose the right type of encoder?

What parameters to pay attention to?

Whether this encoder will work with the built-in decoder (pdf in attachment)? I wrote a simple program and it counts impulses wrong (e.g. 12 24 36)

Sample code here:

void quad_decoder_user_callback_function(int16_t qdec_xcnt_reg, int16_t qdec_ycnt_reg, int16_t qdec_zcnt_reg) { arch_printf( "\n\r DX: "); arch_printf( "%i %i\n\r",qdec_xcnt_reg >> 8,qdec_xcnt_reg & 0xFF); quad_decoder_enable_irq(1); } void quad_decoder_init_enc(void){ QUAD_DEC_INIT_PARAMS_t quad_dec_init_param = {.chx_port_sel = QUAD_DEC_CHXA_P08_AND_CHXB_P09, .chy_port_sel = QUAD_DEC_CHYA_NONE_AND_CHYB_NONE, .chz_port_sel = QUAD_DEC_CHZA_NONE_AND_CHZB_NONE, .qdec_clockdiv = 0, .qdec_events_count_to_trigger_interrupt = 1,}; quad_decoder_init(&quad_dec_init_param); quad_decoder_register_callback(quad_decoder_user_callback_function); quad_decoder_enable_irq(1); }

Attachment Size
EC12E20-24P24C-SW.pdf 69.34 KB

3 months ago

PM_Dialog

Hi adam.stroz,

Please check the DA14531 datasheet Table 3: Absolute Maximum Ratings and Table 4: Recommended Operating Conditions. Given that the encoder can be connected to any of the DA4531 pins, you should check that the output of the input channels are according to DA14531 pin specifications.

I would recommend first checking theUM-B-119: DA14585-DA14531 SW Platform Referenceand section 5.10. Quadrature Decoder Example. Are you able to run the SDK example? Take a look at Table 15 HDK jumper configuration Quadrature decoder.

Thanks, PM_Dialog

3 months ago

adam.stroz 35 points

Hello,

是的,我跑这个例子,它也显示bad values. I run the program on my custom PCB, here are sample readings (the message is sent after turning the encoder by 4 steps, not one as it should be)

DX: 0 4 DX: 0 18 DX: 0 28 DX: 0 37 DX: 0 50 DX: 0 52 DX: 0 70

3 months ago

PM_Dialog

Hi adam.stroz,

Can you please indicate the pinout that you are using? Is it P06 (CHX_A) and P05 (CHX_B)? Did you try to run it in our DK to check if there is any difference?

Thanks, PM_Dialog

2 months ago

adam.stroz 35 points

Currently i'm using this pinout:

#define encoder_sw_port gpio_port_0 #define encoder_a_pin gpio_pin_9 #define encoder_b_pin gpio_pin_8 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// gpio_configurepin(ercoder_sw_port,encoder_a_pin,input_pullup,input_pullup,pid_gpio,true);gpio_configurepin(encoder_sw_port,encoder_b_pin,input_pullup,pid_gpio,true);///// ////////////////////////// quad_dec_chxa_p08_and_chxb_p09.

What do you mean by " Did you try to run it in our DK to check if there is any difference?"

Diagram in attachment.

Attachment Size
ENC.pdf 21.02 KB

2 months ago

PM_Dialog

Hi adam.stroz,

Sorry for the confusion – I meant to put the encoder on the Pro-DK and test it. I assume that you have a custom board.

Can you please use a clean quadrature_decoder project as provided by the SDK and do only the following modifications? The P08 is used for the UART2.

Project location : 6.0.14.1114\projects\target_apps\peripheral_examples\quadrature_decoder\Keil_5

In user_periph_setup.h :

#define UART2_TX_PORT GPIO_PORT_0 #define UART2_TX_PIN GPIO_PIN_5 #define QUADRATURE_ENCODER_CHX_A_PORT GPIO_PORT_0 #define QUADRATURE_ENCODER_CHX_A_PIN GPIO_PIN_8 #define QUADRATURE_ENCODER_CHX_B_PORT GPIO_PORT_0 #define QUADRATURE_ENCODER_CHX_B_PIN GPIO_PIN_9 #define QUADRATURE_ENCODER_CHX_CONFIGURATION QUAD_DEC_CHXA_P08_AND_CHXB_P09

Thanks, PM_Dialog

2 months ago

PM_Dialog

Last comment from adam.stroz :

Quadrature Decoder / WKUP controller SW3 button to start/stop Quadec polling SW2 button to terminate Quadec test Quadrature Decoder Test started!. Press SW2 button to terminate test. Quadec ISR report: > First encoder turn DX: 0002 DY: 0000 DZ: 0000 Quadec ISR report: >Fourth encoder turn DX: 0015 DY: 0000 DZ: 0000 Quadec ISR report: >Eighth encoder turn DX: 0023 DY: 0000 DZ: 0000

" I tested your proposition (a clean quadrature_decoder example, i change only encoder and uart pins), and encoder still doesn't work properly... I see an event only when turn (left or right) encoder four times (sometimes after one turn). In attachment oscilloscope diagrams (A and B encoder pins on blue and yellow lines, the first picture shows first turn, second pictures shows next turns). Maybe i have the wrong type of encoder? "

来自旧论坛帖子的副本:https://support.dialog-semiconductor.com/forums/post/dialog-smartbond-b…

Attachment Size
SDS00001.pdf 12.13 KB

2 months ago

PM_Dialog

你好呀,

This sounds like contact bounce… Our setup had some issues with that too. We fix this by adding a debouncing circuitry. Could you please check this?

Thanks, PM_Dialog