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--- projects:crazyflie:hardware:explained [2013-01-12 15:54]
tobias [Specification]
+++ projects:crazyflie:hardware:explained [2021-06-24 16:49] (current)
kimberly
@@ Line 1: / Line 1: @@
+<WRAP center round important 60%>
+This page has deprecated and will be archived. Please go to [[https://www.bitcraze.io/]].
+</WRAP>
 ====== Crazyflie KIT electronics explained ======
 This section is here to explain all high level electronics used in the Crazyflie.
@@ Line 8: / Line 11: @@
 ===== Battery =====
 {{:projects:crazyflie:hardware:fullriver_671723_hs25c.jpg?200 |}}
-The battery we use is of the type LiPo (Lithium-Polymer). They are currently the most popular battery type for R/C use. The LiPo is hoverer not the safest chemistry and should be handled with care. Failing to do so could make it catch on fire. It is also sensitive to under/over charge, to high discharge/shortage, heat and more. What it is good at however compensates for all these shortcomings as it has among the best power to weight ratios and discharge currents.
+The battery we use is of the type LiPo (Lithium-Polymer). They are currently the most popular battery type for R/C use. The LiPo is however not the safest chemistry and should be handled with care. Failing to do so could make it catch on fire. It is also sensitive to under/over charge, to high discharge/shortage, heat and more. What it is good at however compensates for all these shortcomings as it has among the best power to weight ratios and discharge currents.
 ==== PCM ====
@@ Line 25: / Line 28: @@
 || Over discharge current delay time     || 7.2～11ms  ||
 || Short detection delay time            || 220~380us  ||
-|| Short release condition               || Cut of load  ||
+|| Short release condition               || Cut off load  ||
 || Current consumption                   || Max 0.7uA  ||
 || Suggested max continuous charge/discharge current || 3A  ||
@@ Line 35: / Line 38: @@
 Specification:
-|| Model || Voltage (V） || Capacity (mAH) || Thickness (±0.2) || Width (±0.5) || Height (±0.5) || Weight (g） || Charge Rate || Continues Discharge Rate || Burst (≤5S）||
+|| Model || Voltage (V） || Capacity (mAh) || Thickness (±0.2) || Width (±0.5) || Height (±0.5) || Weight (g） || Charge Rate || Continuous Discharge Rate || Burst (≤5S）||
 || 671723HS25C || 3.7 || 170 || 6.9 ||17 || 23 || 3.9 || 1C-5C || 25C (≥ 80%) || 50C ||
 {{:projects:crazyflie:hardware:fullriver_671723hs25c_wiki.png?500|}}
@@ Line 47: / Line 50: @@
 We have tested several sizes of LiPo batteries, 100mAh to 400mAh, and found out that 150mAh to 250mAh is the sweet spot giving the best flight performance.
-===== Power management =====
+===== Power =====
+==== Power management ====
 {{:projects:crazyflie:hardware:bq24075_wiki.png |}}
 The power management is mainly handled by the [[http://www.ti.com/product/bq24075|TI BQ24075]] power management chip. It handles on/off and charging of LiPo. The BQ24075 has three input limiting modes, 100mA, 500mA and user selectable (currently set to 740mA) which makes it easier to comply to USB standard. It also makes it possible to quick charge if the Crazyflie is connected to a wall adapter. However our 170mAh battery should normally not charge faster then 3C (510mA).
+==== Power distribution ====
+The Crazyflie control board utilizes the separate power plane technique using a 4 layer board. It has proven to work pretty well and we have low ripple currents. However it is not perfect and at some Radio channels we can notice that the motor PWM sometimes is interfering with the Radio.
+There are a number of supplies and grounds
+|| Supply || Range (V)|| Description ||
+|| +BATT || 3.0 - 4.2 || Battery supply voltage ||
+|| VCOM || 3.0 - 5.5 || Supply after power management chip. Can be +BATT or USB voltage ||
+|| VCC || 2.8 or 3.3 || Digital supply voltage. Input is the VCOM supply ||
+|| VCCA || 2.8 || Analog supply voltage, which is filtered.  Input is the VCOM supply ||
+|| GND || 0 || The ground shared by the motor drivers and the battery ||
+|| DGND || 0 || Digital ground. Connected to GND in a start-point fashion. ||
+|| AGND || 0 || Analog ground. Connected to GND in a start-point fashion. ||
+The analog and digital supply uses the TPS79301 adjustable voltage regulator. It is a ultra-low noise 200 mA capable LDO voltage regulator. We choose to use the adjustable variant for both supplies to have maximum tune-ability. This way one can set the output voltage just by changing a couple of resistors. It has also enabled us to make the digital supply switch from 2.8 V to 3.3 V when the micro-USB cable is connected so we can comply the the USB standard.
 ===== MCU =====
 The MCU (Micro Controller Unit) we use, the brain of the Crazyflie, is the ST Microelectronics STM32F103CB. We actually choose this MCU in 2009 and now it is very commonly used by hobbyists and other UAV platforms. The STM32F103CB MCU we run at full speed, 70Mhz, and it has 128Kb flash and 20Kb RAM. As of December 2012 our current firmware takes 46kb flash and 16kb RAM. The RAM can definitely be more optimised so there are plenty of room to implement more algorithms and fun stuff. We use about 40% of its processing power (with a stabilization update loop at 500Hz) and a big chunk of this is because we use a "blocking" I2C driver.
@@ Line 61: / Line 79: @@
 ===== Expansion header =====
 {{:projects:crazyflie:hardware:crazyflie_expansion_header_wiki.png?300 |}}
-The expansion header is located on the left side of the Crazyflie. It is a 10x2 pin 1.27mm (0.05") pitch trough-hole footprint which comes unmounted. The idea with the through-hole is that it makes it possible to mount expansion boards on either or both sides. It would even be possible to stack several on top of each other.
+The expansion header is located on the left side of the Crazyflie. It is a 10x2 pin 1.27mm (0.05") pitch through-hole footprint which comes unmounted. The idea with the through-hole is that it makes it possible to mount expansion boards on either, or both, sides. It would even be possible to stack several on top of each other.
 The header is divided into two parts. The JTAG part, pin 1 to 10, and the buss/power part, pin 11 to 20. The UART RX/TX is located on the JTAG part because on many FTDI based JTAGs it is possible to use one channel for serial communication which can be very handy when debugging.
@@ Line 78: / Line 96: @@
 || 10 || SNRST || System reset ||
 || 11 || EXT_SPI_CS/AIN4 || SPI chip select or analogue in 4 ||
-|| 12 || EXT_SPI_MOSI/AIN5 || SPI Master Out Slave In chip or analogue in 5 ||
+|| 12 || EXT_SPI_MOSI/AIN7 || SPI Master Out Slave In chip or analogue in 7 ||
-|| 13 || EXT_SPI_SCK/AIN6  || SPI clock or analogue in 6 ||
+|| 13 || EXT_SPI_SCK/AIN5  || SPI clock or analogue in 5 ||
-|| 14 || EXT_SPI_MISO/AIN7 || SPI Master In Slave Out chip or analogue in 7 ||
+|| 14 || EXT_SPI_MISO/AIN6 || SPI Master In Slave Out chip or analogue in 6 ||
 || 15 || VCC || Digital supply voltage ||
 || 16 || VCOM || Battery/USB voltage ||
@@ Line 115: / Line 133: @@
 || Motor diameter || 6 ± 0.05 mm ||
 || Motor length || 15 mm ||
-|| Weight || 1.6g approx.||
+|| Weight || 1.7 g approx.||

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