Great Scott! A radiation-tolerant microSD card is designed to withstand the harsh radiation environment encountered in space applications. One such option is the SpaceABLE SD SAFE-series from Reflex Photonics. These SD cards are tested for radiation tolerance and can perform well in the harsh conditions of space.

Keep in mind that radiation-tolerant components may be more expensive and have longer lead times than their non-radiation-hardened counterparts. So it's essential to plan ahead when designing a project that requires radiation-tolerant components.

@docbrown What is a radiation tolerant microSD card I can use

Great Scott! To connect a CMOS imager to the STM32H7XI, you need to use the parallel camera interface supported by the STM32H7 series called DCMI (Digital Camera Interface). This interface allows you to connect CMOS image sensors up to a resolution of 16 Mpix. Here's an outline of the procedure:

Please note that the specific steps and camera settings may vary depending on the CMOS imager you choose. So it's crucial to carefully review the datasheets and available software libraries for generating the necessary configuration.

@docbrown How would I connect a CMOS imager to the STM32H7XI

To connect IC1 (DS3231M+ Real-Time Clock) to U2 (STM32F405RGT6 microcontroller), you need to connect the I2C data line (SDA) and the I2C clock line (SCL). Here's the connection scheme:

Additionally, if you'd like to use the interrupt or square wave functionalities of IC1, you can connect the INT/SQW pin (pin 3) to an appropriate GPIO pin on the STM32F405RGT6 that supports external interrupts. Remember to use appropriate pull-up resistors for the SDA and SCL lines and decoupling capacitors for power supply pins.

@docbrown How would I connect IC1 to U2?

To create a voltage divider that drops 6V to 3.3V, you can use two resistors, R1 and R2, in series. In this case, we'll call R1 the resistor connected to 6V and R2 the resistor connected to GND (position 1069, 44). The output voltage (Vout) is taken across R2.

Using the voltage divider equation, Vout = Vin * (R2 / (R1 + R2)), where Vin = 6V and Vout = 3.3V.

Let's select R2 as a known value, say, 10 kΩ. To find R1, you can rearrange the equation as:

R1 = R2 * ((Vin / Vout) - 1)

Plugging the values into the equation:

R1 = 10 kΩ * ((6V / 3.3V) - 1) R1 ≈ 8.18 kΩ

So, you can pick R1 to be around 8.2 kΩ (a standard value) with R2 at 10 kΩ to achieve a 3.3V output from a 6V input using a voltage divider. Keep in mind that this simple voltage divider is not an ideal solution for a consistent and reliable 3.3V supply because any change in input voltage or load will affect the output voltage as well. Consider using a voltage regulator if you need a stable voltage supply.

@docbrown what is R1 value if I want to divide 6V to 3.3V

Great, now that we know R4 is 10kOhm, we can calculate the value of C3 for a 500kHz cutoff frequency using the formula:

C = 1 / (2 * PI * R * cutoff_frequency)

C = 1 / (2 * PI * 10,000 * 500,000)

C ≈ 3.18e-12 F

So, the value of C3 should be approximately 3.18 pF to achieve a cutoff frequency of 500 kHz in the low-pass filter configuration.

@docbrown R4 is 10kOhm

To determine the value of C3 for a 500kHz cutoff frequency, we also need to know the value of the resistor connected to C3 in the low-pass filter configuration. Based on the provided netlist, it looks like R4 is connected with C3.

From the netlist: Net 0 connects +6V_V_MON:P1, , +6V_V_MON:P1, C3:P2, R4:P1, U2:P62 Net 9 connects R2:P2, R1:P1, R4:P2

Assuming C3 and R4 form a first-order low-pass filter, we can use the formula to calculate the capacitor value:

cutoff_frequency = 1 / (2 * PI * R * C)

Where R is the resistor value and C is the capacitor value. Rearranging for C, we get:

C = 1 / (2 * PI * R * cutoff_frequency)

For a 500kHz cutoff frequency, please provide the value of R4, and I can help you calculate the value for C3!

@docbrown If C3 is part of a low pass filter, what value should it be to provide a cutoff frequency of 500kHz?