Gerda & Vendan
Gerda Gerda
Vendan Vendan
Gerda Gerda
Hey Vendan, I’ve been sorting through a hundred infant charts and it got me thinking—what if we built a little automated guardian that logs vitals, tracks sleep cycles, and even plays the right lullaby at the right time? It could cut down on paperwork and keep the babies happy. You up for tinkering with a new baby‑monitoring machine?
Vendan Vendan
Sounds like a sweet idea, but I’ve got a lot on my plate already. If you can draft a rough design or list the key specs, I’ll take a look and see if it’s something I can squeeze into my workshop. Just keep the plan tight and avoid any fancy gizmos that need a whole new battery pack.
Gerda Gerda
Okay, here’s the outline, no fluff, no extra batteries. 1. **Core unit** – 3‑axis accelerometer + 5‑digit LCD. *Power: single 9 V cell (same as the old patient monitor). *Mount on the crib frame with a quick‑release clip. 2. **Sensors** – - Pulse oximeter probe on the foot (same probe used for adults). - Temperature sensor in the mattress. - Ambient sound level meter (tiny MEMS mic). 3. **Software** – - Simple microcontroller (ATtiny85). - Firmware that logs data to an SD card (Micro SD). - Auto‑mute lullaby module (tiny speaker) that plays a preset 20‑sec lullaby when heart rate < 80 bpm and temperature > 36.5 °C. 4. **Data handling** – - Every 30 s, append to SD card in CSV format. - On power‑off, it writes a header row with infant ID, date, and shift. 5. **Interface** – - 2‑way keypad for infant ID entry (no touch). - Simple LED status: green = normal, amber = watch, red = alarm. No extra battery packs, no wireless modules, just a solid, low‑power design that you can snap into the existing crib. If you need a schematic, let me know, and I’ll get it to you.
Vendan Vendan
Nice rundown, but 9 V might choke the oximeter and the mic. Think about a low‑current regulator or a fresh 9 V with a fresh battery each shift. If you give me the exact parts numbers and a pin‑out sketch, I can spot any power hiccups and see if the microcontroller will keep up with the logging. Let’s keep the design tight and avoid any extra modules that will make the unit heavier than a baby’s blanket.
Gerda Gerda
Sure thing, here’s the barebones list and layout: **Power** - 9 V alkaline (fresh each shift) – just a single cell. - LM7805 (5 V regulator) – pin‑out: 1‑IN, 2‑OUT, 3‑GND. - 0.33 µF bypass on regulator output. - No battery pack needed, just clip the 9 V into the regulator input. **Microcontroller** - ATtiny85 (part # 00000202). *Pin‑out for this project:* – PB0 (Pin 1) → Oximeter data line (MAX30102, I²C SDA) – PB1 (Pin 2) → Oximeter clock (I²C SCL) – PB2 (Pin 3) → SD card MOSI – PB3 (Pin 4) → SD card MISO – PB4 (Pin 5) → SD card SCK – PB5 (Pin 6) → SD card CS – GND (Pin 7) → GND – VCC (Pin 8) → 5 V from regulator **Sensors** - MAX30102 (pulse oximeter, part # 0E3D). *VCC* to 5 V, *GND* to GND, *SCL* to PB1, *SDA* to PB0. - DS18B20 (temperature sensor, part # DS18B20). *VCC* to 5 V, *GND* to GND, *DQ* to PB4 (with 4.7 k pull‑up to 5 V). - SPW04 MEMS mic (part # SPW04). *VCC* to 5 V, *GND* to GND, *OUT* to PB5 (via 1 k resistor to limit current). **Speaker** - 8 Ω piezo (part # 8ΩPZ). *Positive* to PB2, *negative* to GND, controlled through a 1 k resistor to keep it light. **SD Card** - Micro SD card socket (part # SD-SOCKET). Connect as per pin‑out above; use a 1.8 V to 5 V level shifter (just a simple voltage divider on MOSI and SCK). **Misc** - 22 pF capacitor between VCC and GND of the microcontroller for decoupling. - 10 k pull‑up on SDA/SCL lines. - Keep the whole assembly under 100 g; all components are surface‑mount and the regulator is tiny. That’s the whole thing in one neat block. No extra modules, no heavy batteries, just a 9 V cell and a regulator. Let me know if the regulator’s dropout is too high when the 9 V cell is low, and we can switch to a low‑drop regulator.