Production Arduboy Schematic

The schematic is the top post of this thread! Are they looking for board files? Confused!

@bateske is it possible to get the eagle schematic file (not looking for the board file) ? I’d like to make a few changes for better guidance.

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Maybe? Can you write arduboy.com/contact with some more details and I’ll see if I can dig it up. (It’s actually in a backup hard drive by this point)

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:+1: Filled in the contact form :slight_smile:

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Hello I am new here but I have a question about the schematic of the arduboy.
What is the value of the 3 resistors and 3 diodes on pin PB5, PB6 and PB7.
I don’t understand what there function is.

I’m trying to understand how the schematic is build for a project at my university, but even my teacher doesn’t understand this part.

I hoop that someone can help me.

That’s the RGB LED - resistor values are going to depend on the LED(s) you use (pinout table from https://community.arduboy.com/t/12-arduboy-compatible-system/236/359):

Arduboy function

Arduboy / Leonardo / Micro

OLED CS

12 PORTD6

OLED DC

4 PORTD4

OLED RST

6 PORTD7

SPI SCK

15 PORTB1

SPI MOSI

16 PORTB2

RGB LED RED

10 PORTB6

RGB LED GREEN

11 PORTB7

RGB LED BLUE

9 PORTB5

RxLED

PORTB0

TxLED

PORTD5

BUTTON UP

A0 PORTF7

BUTTON RIGHT

A1 PORTF6

BUTTON LEFT

A2 PORTF5

BUTTON DOWN

A3 PORTF4

BUTTON A (left)

7 PORTE6

BUTTON B (right)

8 PORTB4

SPEAKER PIN 1

5 PORTC6

SPEAKER PIN 2

13 PORTC7

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Like @uXe said it’s a RGB LED (Light emitting Diodes) which has a red, green and blue LED in a single package. The Arduboy uses one of the common anode type meaning the anodes (positive side) of the red, green and blue LED are tied together internally (this is the longest pin).

The resistors function is to limit the current flowing through the LEDs. I don’t know which values Arduboy exactly uses. But it depends on the RGB LED being used anyway. For a good white balance you’d have to check out the RGB LED’s datasheet. But if you’re not to picky about that you could just use a couple of 1K ohm resistors. If you want them extremely bright you could use some 220 ohm resistors.

When you get a common anode RGB LED get a diffused one (miky plastic case) and not a clear one.

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The actual values that the Arduboy uses are 220 ohm on all 3 LEDs but these aren’t really a good choice. They should be balanced for each colour because each colour operates at a different voltage, and the brightness relative to the current will be different for each as well. Also, the Arduboy’s LEDs tend to be a little bright overall.

As @uXe said, the resistor values will depend on the particular RGB LED that you use. It will also depend on the supply voltage (such as whether you run from regulated 5V or a battery voltage). So, it’s best to experiment to find suitable values. I would start with 1K for red and blue, and 3.3K for green.

P.S. The schematic should have used the LED symbol (with the “light emission” arrows), like LED1 and LED2, for the RGB LEDs, instead of the regular diode symbol.

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Thanks for the help,

But I still have a question about the battery protection.

Can someone tell me which components are used to make the battery protection and what the “FTD2017” is?

I don’t understand way this component is short to it self.

Also what is the component in the middel of the battery protection? There is no reference to is or info what it is.

Thank you in advance for the help.

The FTD2017 is just two MOSFET transistors contained in the same package.

The other component is a dedicated one cell lithium-ion/polymer battery protection IC. It’s probably a DW01-P or similar.

http://pdf.datasheetcatalog.com/datasheet/sanyo/ds_pdf_e/FTD2017.pdf

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3 posts were split to a new topic: Troubleshooting homemade Arduboy schematic

Sorry to resurrect an old topic, but I was poking around the sound hardware last night and I noticed C12 (the DC blocking cap in series with the pizeo element) was replaced with a 220-ohm resistor.

Is there a more up-to-date schematic or is that the only change?

7 posts were split to a new topic: Display for homemade Arduboy

I decided to necro-post instead of starting a new topic for this.

In looking over a homemade Arduboy design for @mameise, I noticed a few questionable component values used in the real Arduboy that I’ve never evaluated before.

  1. Resistor R7, connected to the PROG pin of the MCP73831 charge controller, determines the battery charge current. Its value is 2K, which will result in a current of 500mA. I believe the recommended charge current for the type of LiPo battery used for the Arduboy is 1C (a current of 1mA per 1mAh battery rating). The Arduboy battery is rated 180mAh so a 1C charge current would be 180mA. 500mA is 2.8 times 1C, or 2.8C. That seems quite excessive to me and probably isn’t very good for the life of the battery. Some LiPo batteries meant for RC use specify safe charge rates of up to 3C but I can’t find any recommendations that regular LiPo batteries be charged at more than 2C (and most say stay at, or below, 1C).

  2. The part number for the battery protection IC isn’t given in the schematic but, based on the wiring, it appears to be a DW01-P or equivalent. If this is the case, the DW01 datasheet recommends that R11 be 100ohm but the Arduboy uses 10K.

    This resistor, along with C11 is to filter out noise on the Vcc power input. The datasheet states that Icc (the current draw through the Vcc pin) is typical 3uA, maximum 6uA. At this current, the voltage drop across a 100ohm resistor would be a negligible 0.3mV to 0.6mV but with 10K it would be 30mV to 60mV. Since the voltage on Vcc is used to determine over-voltage and under-voltage, I wonder if the battery is still properly protected with such a difference between Vcc and the actual battery voltage?

  3. Again if the battery protection IC is equivalent to a DW01-P, resistor R6 is on the CS (Current Sense) pin. The datasheet says this resistor should be 1K but the Arduboy uses 10K.

    The datasheet states:

    In normal mode, the DW01-P continuously monitors the discharge current by sensing the voltage of CS pin. If the voltage of CS pin exceeds the overcurrent protection voltage (VOIP) beyond the overcurrent delay time (TOI1) period, the overcurrent protection circuit operates and discharging is inhibited by turning off the discharge control MOSFET.

    So if the resistor on CS is 10 times the recommended value, I wonder how that affects the over-current protection?

Does @bateske or anyone else have any information or thoughts about this?

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5 years, no battery failures other than mechanical ones.

For any issues use arduboy.com/contact

But any ideas why you made those design choices?

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@bateske,
Can you at least tell us what specific battery protection IC the Arduboy uses, so we can determine what resistor values are recommended for it?

R5402N

image

Are mistakes choices?

Are mistakes not by definition the unintended consequence of some purposeful action which was undertaken by choice?
Conversely, can a mistake be a mistake if someone didn’t make a decision of some kind?

(Or have I just been on the skooma again?..)

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