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Hello,
I have just received the CY8CKIT-042 PSoC 4 Pioneer kit and I just completed my first video... Blinking an output led!
I got the the actual example from the video to compile and work!
So since the blinking led is an RGB led connected to outputs P0[2], P0{3] and P1[6] of the PSoC4, I couldn't help noticing that the P0[2] and P0[3] pins of the RGB are connected to 1.5K resistor, but P1[6] pin is connected to a 2.2K resistor? If the 3 leds in the RGB led have the same power consumption, why is P1[6] pin connected to a higher value resistor?
Please view attached images!
Also, in the kit I just recieved what PSoC MCU is it exactly....
Is it the PSoC 4200, PSoC 4200M, 4200-L or the 4200 DS???
Thank you for all help and support!
r
Solved! Go to Solution.
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PSoC 4 MCU
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RoRo,
As /odissey1 indicated the resistors are to trim the current into each of the LED.
LED intensity is dependent on current.
Here is a part of the datasheet for the LED part. Notice that the RED LED has an average 2.0V forward drop (Vf) but the GREEN and BLUE LEDs have a average forward drop of 3.2V.
Using the Vf(avg) value for each R (P1.6) G (P0.2) and B (P0.3) LEDs:
Assumptions
P4_VDD = 4.8V
LEDs are GND'd through the port pins for illumination.
I (of LED) = (P4_VDD - Vf (of LED))/ R (of LED)
I (of R LED) = (4.8V - 2.0V) / 2.2K = 1.27mA
I (of G LED) = (4.8V - 3.2V) / 1.5K = 1.07mA
I (of B LED) = (4.8V - 3.2V) / 1.5K = 1.07mA
The IC is a 4200. No M, L or DS part.
"Engineering is an Art. The Art of Compromise."
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RoRo,
The CY8CKIT-042 comes with P4200. Resistors are different to match the brightness of LEDs.
You may find an annotation component useful for identifying pins on the kit
KIT-042: annotation component for CY8CKIT-042 Pioneer Kit
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RoRo,
As /odissey1 indicated the resistors are to trim the current into each of the LED.
LED intensity is dependent on current.
Here is a part of the datasheet for the LED part. Notice that the RED LED has an average 2.0V forward drop (Vf) but the GREEN and BLUE LEDs have a average forward drop of 3.2V.
Using the Vf(avg) value for each R (P1.6) G (P0.2) and B (P0.3) LEDs:
Assumptions
P4_VDD = 4.8V
LEDs are GND'd through the port pins for illumination.
I (of LED) = (P4_VDD - Vf (of LED))/ R (of LED)
I (of R LED) = (4.8V - 2.0V) / 2.2K = 1.27mA
I (of G LED) = (4.8V - 3.2V) / 1.5K = 1.07mA
I (of B LED) = (4.8V - 3.2V) / 1.5K = 1.07mA
The IC is a 4200. No M, L or DS part.
"Engineering is an Art. The Art of Compromise."
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