mili is 1/1000 1mA = 0.001 A k is 1000 1kO = 1000. O
- If your circuit draws 35mA, a battery with a 3400mAh rating can be expected to last about 4 days. explain? maybe later you should know what i mean
- If you connect 4 1.5v AAs 2000mA batteries along the + line, that is believe it or not a 1.5v battery still. But it can send something made up on a website
- AA battery 1.5v and up to 50mA. But they write it 1500mAh - mili amp hour? Which means? I can be exact, it means it can supply 1500mA in one hour. That is great. A typical arduino uses 80mA - that means no go. Ok a typical Arduino uses 25mA lets say. So those batteries can power it. That means a 1.5v stepped up can power it for 60 hours by my reconning. And 60 hours is what exactly? 2.5 days.
- You can connect two power packs in parallel to create more current (double so called), but with the same voltage.
Here is another example, this time from the web:
- A 12V 2400mAh - circuit 12V 300mA => 2400/300 = 8 hours
Someone suggests wiring a series diode to the 5v battery in ..
Someone suggests using the barrel and it's regulator is wasting battery and heat and stuff.. and resources to climb above the 6V.
Someone suggests 6 AAs into the barrel is the way to go as that's what it's for. Other above is to fry stuff if you ..
Someone suggests using less batteries 3 and a DC booster. You loose the least then. I believe that is direct in no regs.
Someone suggests 3 AAs direct to vin, that way no power wasted on reg, and you get 6 months..
If you use 12V on the reg, you are throwing away half the power as heat.
Some interesto stuff there. But me being me wants to have a battery backup supply.
Ah very interesting, most USB power banks require a minimum load or they shut off, therefore, you need to periodically pulse a high power LED. soooo maybe it's best to go battery only? instead of the power bank. Here is an example: This particular arrangement works for my XiaoMi PowerBank (20A). Total power drawn is roughly 3.5mAh (per hour), so its not too bad. Assuming it runs at 5v (from the USB)... 0.0035Ah x 5v = 0.0175Wh If you run it for 24 hours.. 0.0175Wh x 24 = 0.42Wh Assuming the powerbank only holds 15A (x3.7v = 55Wh) ... this circuit will finish the battery in about 4 months.
Use PWM to reduce power draw. Here are some power saving notes for the chip http://www.gammon.com.au/power
Reset Pin: This is pulled up with a 10K resistor to help prevent spurious resets in noisy environments. if the user presses the reset button or if a reset is issued from the USB bridge.
USB power => 5v in => Vin is also 5v
Barrel power => 9-12V is Vin => Vin is also this
No power => Vin is the power in
3.3 V => generated from the FTDI chip
The ard has 4 ways to power it.
- USB is 5V in or else. There is a current limit of 250mA or 500mA depending on moon phase.
- The barrel jack is +7 to 12v in, and the positive is the central part of the jack Maybe min 6V would be enough.
- Vin as above, but can be used in conjunction to the above if you need to split, but in general don't use both
- The 5V pin, it is for output normally, but you can input it if you know it is 5V and nothing but
Interestingly the ard has a comparison circuit. So if the USB and barrel is powered, the power comes from the barrel first, and then switches over to the usb. Why? Why not. I would like the reverse.
There is a P MOSFET so I just need a P MOSFET and switch around the inputs right? Anyway the P MOSFET has:
5V USB
|
|
barrel ----[FDN340P]
|
+--- 5V in to ard
In the above case the barrel is also connected to an opamp? comaritor that compares the input to 3V3 for something else.
I guess you could keep the barrel and then instead of USB powered the USB 5v could be applied directly to the Vin pin - that way you would get your order or precedence, but the Vin line is not protected at all..
There is also the 5V line, but you normally draw there instead of power there.
In fact that don't mention applying there and the barrel just one or the other.
There are some good ways to destroy the ards here.
The ard doesn't require 5v per se, but the Atmel chip needs 1.8V to 5.5V. Anything below 4V will mean the 3.3V regulator will not work, and also the the Atmel chip will not work reliably at high clock speeds, so some 3.3V ards use 8MHz instead of 16MHz.
From: https://www.allaboutcircuits.com/technical-articles/understanding-arduino-uno-hardware-design/
The 5V regulator is the NCP1117ST50T3G and the Vin of this regulator is connected via DC jack input through the M7 diode
Another source of 5V is USBVCC which is connected to the drain of an FDN340P, a P-channel MOSFET, and the source is connected to the 5V net. The gate of the transistor is connected to the output of an LMV358 op-amp used as a comparator
The comparison is between 3V3 and Vin/2. When Vin/2 is larger, this will produce a high output from the comparator and the P-channel MOSFET is off. If there is no Vin applied, the V+ of the comparator is pulled down to GND and Vout is low, such that the transistor is on and the USBVCC is connected to 5V.
It's the chip. 28 pins. 8bit RISC. 16MHz crystal, 2 22pF caps, 10uF cap, and 10kR? You can use it. Pu has the bootloader already.
The other chip ATmega16U2 converts USB to UART that the ATmega328 understands. The 16U2 is programmed to do this in this case.
The micro is based on slightly different ATmega32U4. 20 pins, 16MHz, micro usb, ICSP header, reset button. The 32U4 has built in usb, unlike the one above, so no need for USB controller. 5v. Input 7-9v. 20mA per IO, or 50mA at 3.3v pin. I think the ICSP header is for programming the board, and also
Digital Pins 0 1
- Serial In/Out - TX/RX (dark green)
- These pins cannot be used for digital i/o (digitalRead and digitalWrite) if you are also using serial communication (e.g. Serial.begin).
Digital Pins 2-13 (green) Digital Pins 3 5 6 10 11
- pwm Digital Pins 10 11 12 13
- spi SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication, which, although provided by the underlying hardware, is not currently included in the Arduino language. Digial Pin 13
- when high led is also high
Analog In Pins 0-5 (light blue) Analog Pins 4 5
- I2C 4=SDA 5=SCL
- I2C XTR=SDA XTR-1=SCL = 18=SDA 19=SCL .. maybe they are duplicates for handyness .. seems for shields
pinMode(led_pin, OUTPUT);
analogWrite(led_pin, 0) means a signal of 0% duty cycle. OFF
analogWrite(led_pin, 127) means a signal of 50% duty cycle. 50/50
analogWrite(led_pin, 255) means a signal of 100% duty cycle. ON
PROGMEM stores in PROGMEM ahahaha ha thanks, Please note that variables must be either globally defined, OR defined with the static keyword, in order to work with PROGMEM.
You can use this for strings to serial anyway .. Serial.print(F("Write something on the Serial Monitor that is stored in FLASH"));
You can use this for anything that does not change..
Here we go ..
Flash memory is used to store your program image and any initialized data. You can execute program code from flash,but you can't modify data in flash memory from your executing code. To modify the data, it must first be copied intoSRAMFlash memory is the same technology used for thumb-drives and SD cards. It is non-volatile, so your program will stillbe there when the system is powered off.
stack vars, global vars, static vars live here.
It's a bit slower than SRAM 1 byte at a time. You can use apis for it. I guess handy to store stuff between restarts?
Flash, SRAM, EEPROM
Uno: 32k, 2k, 1k
Mega: 256k, 8k, 4k
0x0..0xFF = 0 to 256
0xFF = 1111 1111 = 1 byte
1024 bytes = 1k
boolean 0xFF = 1 byte = true(1) or false(0)
char 0xFF = 1 byte = -128 .. 127
unsgined char 0xFF = 1 byte = 0 .. 255
byte 0xFF = 1 byte = 0 .. 255
uint8_t 0xFF = 1 byte = 0 .. 255
int 0xFFFF = 2 byte = +-32,000
short 0xFFFF = 2 byte = +-32,000
unsigned int 0xFFFF = 2 byte = 0 .. 65000
word 0xFFFF = 2 byte = 0 .. 65000
uint16_t 0xFFFF = 2 byte = 0 .. 65000
long 0xFFFF-FFFF = 4 byte = +-2,000,000
unsigned long 0xFFFF-FFFF = 4 byte = 0 .. 4,000,000
uint32_t 0xFFFF-FFFF = 4 byte = 0 .. 4,000,000
float 0xFFFF-FFFF = 4 byte = +- something oh dear
double 0xFFFF-FFFF = 4 byte = +- something oh dear
SDA = serial data SCL = serial clock i will never remember these accrs
0v 0v
| | small
ARD =========================/\/\/===5V
|
0v maybe the rest just reads? maybe 0v is for bus masters.
The I2C bus relies on open drain technology. Except for one special case in conjunction with the high speed mode no I2C device is allowed to drive the bus, i.e. to send a 1 by putting voltage on the bus. Instead, the bus is terminated to a high level, e.g. 5 V and both lines, SCL and SDA, remain there during idle mode. A device sends a 0 by pulling the bus to ground level. A 1 is sent by doing nothing, i.e. leaving the bus at high level. The termination of I2C lines is achieved by connecting the bus to the reference voltage of the bus over an appropriate resistor. Missing or wrong termination is the source of many field problems. As a rule of thumb, the higher the termination the better the signals. On the other hand a high termination bares a potential risk of damaging components. By the way, in I2C engineering terms a high termination means a strong pull-up to VCC which translates into a low value for the resistor.
Here is an example output
LEN = 11
START_H: 69
START_L: 34
DATA_H: 9
DATA_L: 25
DATA_LEN = 6
DATA: 0x40 0x04 0x05 0x38 0x48 0x75
DATA: 64 4 5 56 72 117
LEN = 0000 1011
START_H: 0100 0101
START_L: 0010 0010
DATA_H: 0000 1001
DATA_L: 0001 1001
DATA_LEN = 0000 0110
DATA: 0x40 0x04 0x05 0x38 0x48 0x75
DATA: 64 4 5 56 72 117
I don't know what the START_H START_L DATA_H DATA_L is, but DATA_LEN and DATA makes sense I will guess: If len is 6 => 2 tag device, and 4 tag code If len is 4 => 2 tag device, and 2 tag code Some IRs send the same code twice. So you could probably ignore that.
Some more info:
start signal high time / start high/long duration start signal low time / start low/short duration bit high time / logic long duration bit low time / logic short duration
whatever they are it seems they are needed, strange, anyway you don't need to send the msg twice, phew
Notice that there are series resistors in the D+ and D- USB lines. These provide the proper termination impedance for the USB signals. Z1 and Z2 are voltage-dependent resistors (VDRs), also called varistors. They are used to protect the USB lines against ESD transients.
Why USB data series resistors http://www.eevblog.com/forum/projects/why-usb-data-series-resistors/
USB Developers FAQ http://www.usb.org/developers/usbfaq#sig6
# H1
## H2
### H3
#### H4
##### H5
###### H6
Alternatively, for H1 and H2, an underline-ish style:
Alt-H1
======
Alt-H2
------
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