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| STM32F103 min system with USB-TTL converter? |
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| bjdhjy888:
I have followed your suggestions and managed to re-do the layout. Parts are now much closer to the STM32, resulting in way more vias used. Is this normal? I was concerned when I used extra vias. And, is my overall layout normal? Or, too messy? I did not change my schematic. Will pour copper once there's no issues. Below please find my latest layout. Please let me know if they are okay. Thank you!!! |
| thm_w:
--- Quote from: bjdhjy888 on August 16, 2019, 01:47:55 am ---Parts are now much closer to the STM32, resulting in way more vias used. Is this normal? I was concerned when I used extra vias. And, is my overall layout normal? Or, too messy? --- End quote --- C3 and C4 can be swapped to remove one via. But yes its normal to use vias, there is no cost to you to use an extra via. If you are really lazy, your layout will look autorouted and have a lot of vias, but really, if it works its not too important for hobby use. Your layout is a lot cleaner now. |
| bjdhjy888:
--- Quote from: mariush on August 16, 2019, 12:51:58 am ---The board's a bit of a mess... Get your oscillators closer to the ICs ... get your capacitors closer to the oscillators/crystals. I'd leave space to lay the 32kHz crystal flat on the board... maybe solder it to a third pad with a bit of solder, or have a loop of wire keep it from vibrating or hitting the board. careful with 1117 regulators.... some are unstable if the output capacitance has too low ESR ... some 1117 linear regulators require ESR on output between 0.1 and 1 ohm ... a ceramic capacitor on output will have too low esr... so either add a tiny resistor in series with the output capacitor , something like 0.22... 0.47 ohm or whatever, or just use a regular electrolytic capacitor (ex a 10..100uF 10v electrolytic ) or just use a better linear regulator. add some decoupling capacitors between vin and ground on your micro ... a 100nf ceramic (0.01uF) 200 ohm is kinda non standard value... no need for such value for a status led... i'd say just use 330 ohm or even 470 ohm... more common value. I wouldn't use surface mounted electrolytics (c9)... i'd suggest plain boring through hole, or polymer surface mount --- End quote --- Thank you for your reply. I just ordered some SMD resistors that are of 220 ohm. I guess this voltage divider would be fine? p.s.: my schematic pictures seem gone. What happened? :-[ |
| bjdhjy888:
I have decided to add MPU-6050 to my STM32 min. system, before I send it to my PCB fabrication facility. Since I have never designed anything for MPU-6050, I did a research. What I've learned: - I need to draw a schematic for my MPU-6050, as per Invensense's datasheet on page 22 at https://www.invensense.com/wp-content/uploads/2015/02/MPU-6000-Datasheet1.pdf - I need to add this MPU-6050 circuit to my exisiting STM32 schematic - I need to use I2C to connect my STM32 with my MPU-6050, which only requires 4 wires to be connected: VCC, GND, SDA, SCL - I need to flash a .hex file to my STM32, which contains serial port codes. So, I will be able to read MPU data through STM32, via my microUSB cable, then visually see the data in my Serial Port software on my PC's monitor. Questions: 1. Are my above logic correct? 2. Is my schematic below for my MPU-6050 correct? I supposed this was correct, so I updated my schematic, by adding this MPU. I also wired 4 pins of my header. Would anyone please help me review my schematic and layout? I need to get it manufactured once it's free of mistakes. Thanks so much! |
| thm_w:
You can use PB8 and PB9 on the STM32 but then you will have to use software control for the I2C pins. If you want the option of hardware/software I2C, then you can use PB10/PB11 (SCL SDA as you can see on your schematic symbol). |
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