Download board files

Files for version 1. Pick what you came for.

Share jotter

Check access before sharing the link.

Who can open this board

Anyone can open this board. No sign-in is required.

This link opens the latest version. Copying it does not grant additional access.

Loading…

README

Jotter

Requirements

  • micro usb port for charging and for updating firmware
  • 3.7V from a lipo battery
  • lipo charging circuitry through a micro usb port
  • bluetooth low energy beacon receiver and transmitter for positioning and ideally multilateration
  • MCU to handle bluetooth beacon code
  • accurate real time clock
  • sd card for storing data; consider storing the unit id number on the sd card
  • mems microphone on front for capturing talking of others
  • mems microphone on the back for capturing talking of user
  • MCU for DFT processing of the audio signals
  • IrDA or similar for transmitting and receiving unique IDs to identify users facing users
  • MCU to handing IrDA
  • accelerometer to identify leaning and sitting
  • pressure sensor to identify sitting and standing, usually these are only accurate to within 1 meter, which might not be good enough
  • Wi-Fi capability for updating firmware, changing settings, and downloading data
  • Any LEDs? charging, Wi-Fi transmission
  • Any Buttons? Wi-Fi mode

RTC

DS3231*

  • Arduino Library: Rtc by Makuna, Sodaq_DS3231

DS3231SN

  • has temperature compensated crystal oscillator (may need this for cold temps)
  • TCXO:Yes
  • Alamrs:2
  • $9.97@1, digi-key
  • $6.59@100, digi-key
  • $2.50@10, aliexpress

Coin Cell Retainer/Holder

  • Battery:CR2032
  • Battery Diameter:20mm

BU2032

BU2032-1-HD-G

  • Type:through hole holder
  • $0.83@1, digi-key
  • $0.69@100, digi-key

BU2032SM-HD-G

  • Type:surface mount holder
  • $0.87@1, digi-key
  • $0.76@100, digi-key

BK-912

  • Type:surface mount retainer
  • Notes:easy replacement
  • $0.33@1, digi-key
  • $0.29@100, digi-key

BK-913*

  • Type:through hole retainer
  • Notes:easy replacement
  • $0.35@1, digi-key
  • $0.30@100, digi-key

BK-888

  • Type:through hole retainer
  • blocks inner side
  • easy replacement
  • $0.39@1, digi-key
  • $0.33@100, digi-key

LDO

  • Voltage 3.3V
  • needed for running the esp8266 microprocessor and others
  • ESP8266 typical -- Modem-Sleep is 15mA with not much load -- Wi-Fi Transmission could be up to 170mA, but it is unclear if this is an instantaneous load

AMS1117-3.3**

  • Package:SOT-223
  • Current: 1100mA
  • Input Voltage: Up to 6V
  • Dropout Voltage: 1100mV@800mA
  • $1.58@50, aliexpress

SPX3819M5-L-3-3/TR**

  • Package: SOT-23-5
  • Current: 500mA
  • Input Voltage: Up to 16V
  • Dropout Voltage: 340mV@500mA
  • $0.72@1, digi-key
  • $0.49@100, digi-key

MCP1700T-3302E/TT

  • Package: SOT-23-3
  • Current: 250mA
  • Input Voltage: Up to 6V
  • Dropout Voltage: 178mV@250mA
  • $0.37@1, digi-key
  • $0.28@100, digi-key

TC1262-3.3VDBTR

  • Package: SOT-223-3
  • Current: 500mA
  • Input Voltage: Up to 6V
  • Dropout Voltage: 350mV@500mA
  • $0.51@1, digi-key
  • $0.39@100, digi-key

MIC5528-3.3YMY-TR

  • Package: 6-UFDFN (1.2x1.2)
  • Current: 525mA
  • Input Voltage: 2.5V to 5.5V
  • $0.19@1, digi-key
  • $0.14@100, digi-key

NCP161AMX330TBG

  • Package: 4-XDFN (1x1)
  • Current: 450mA
  • Input Voltage: 1.9V to 5.5V
  • Dropout Voltage: 150mV@450mA
  • $0.46@1, digi-key
  • $0.22@100, digi-key

LiPo Battery

  • 3.7V

100mAh

  • Weight: 3g
  • Size: 11.5mm x 31 x 3.8mm / 0.45" x 1.2" x 0.15"
  • 4mA@24hr
  • 10mA@10hr
  • $5.95@1, Adafruit
  • $4.76@100, Adafruit

150mAh

  • Weight: 4.65g
  • Size: 19.75mm x 26.02mm x 3.8mm / 0.77" x 1.02" x 0.14"
  • 6mA@24hr
  • 15mA@10hr
  • $5.95@1, Adafruit
  • $4.76@100, Adafruit

350mAh

  • Weight: 7.9g
  • Size: 36mm x 20mm x 5.6mm / 1.4" x 0.8" x 0.22"
  • 14mA@24hr
  • 35mA@10hr
  • $6.95@1, Adafruit
  • $5.56@100, Adafruit

500mAh**

  • Weight: 10.5g
  • Size: 29mm x 36mm x 4.75mm / 1.15" x 1.4" x 0.19" -- Little larger than a US Quarter
  • 20mA@24hr
  • 50mA@10hr
  • $7.95@1, Adafruit

1200mAh*

  • Weight: 23g
  • Size: 34mm x 62mm x 5mm / 1.3" x 2.4" x 0.2"
  • 50mA@24hr
  • 120mA@10hr
  • $9.95@1, Adafruit

2000mAh

  • Weight: 34g
  • Size: 60mm x 36mm x 7mm / 2.4" x 1.4" x 0.3"
  • 83mA@24hr
  • 200mA@10hr
  • $12.50@1, Adafruit
  • $10.00@100, Adafruit

2500mAh

  • Weight: 52g
  • Size: 2" x 2.55" x 0.30" (51mm x 65mm x 8mm)
  • 104mA@24hr
  • 250mA@10hr
  • $14.95@1, Adafruit
  • $11.96@100, Adafruit

LiPo Charger

MCP73831/2**

  • Used by Adafruit
  • Package: SOT-23-5
  • Max Charge Current: 500mA
  • Max Input Voltage: 6V
  • $0.56@1, digi-key
  • $0.42@100, digi-key

MAX1555EZK+T

  • Package: SOT-23-5
  • Max Charge Current: 340mA
  • Max Input Voltage: 7V
  • $2.03@1, digi-key
  • $1.34@100, digi-key

MCU - Core

ATSAMD11

  • USB: Yes
  • VCC: 1.62V - 3.63V
  • Current Consumption Idle: 1.8mA
  • Current Consumption While: 3mA
  • Current Consumption CoreMark: 4mA
  • Program Memory: 16KB
  • CPU Frequency: 48MHz

ATSAMD11C

  • SERCOM: 2
ATSAMD11C14A
  • Package: 14-SOIC
  • $2.32@1, digi-key
  • $1.69@100, digi-key

ATSAMD11D

  • SERCOM: 3
ATSAMD11D14A
ATSAMD11D14A-SSUT**
  • Package: 20-SOIC
  • $2.54@1, digi-key
  • $1.85@100, digi-key
ATSAMD11D14A-MUT*
  • Package: 24-QFN (4x4)
  • $2.65@1, digi-key
  • $1.93@100, digi-key

ATSAMD21

  • USB: Yes
  • VCC: 1.62V - 3.63V
  • Current Consumption Idle: 2.2mA
  • Current Consumption While: 4mA
  • Current Consumption CoreMark: 7mA
  • Program Memory: 32/64/128/256KB
  • CPU Frequency: 48MHz
  • I2S: Yes

ATSAMD21E

  • SERCOM:4
  • ADC:10
ATSAMD21E18A
  • Program Memory: 256KB
ATSAMD21E18A-MUT
  • Package:32-VFQFN
  • $5.30@1, digi-key
  • $3.88@100, digi-key
ATSAMD21E15B-AUT
  • Package:32-TQFP (7x7)
  • $3.16@1, digi-key
  • $2.32@100, digi-key

ATSAMD21G

  • SERCOM:6
  • ADC:14

ATSAMD21J

  • SERCOM:6
  • ADC:20

LPGA

  • Custom Reprogrammable Circuit Design

ICE40LP384-SG32


MCU - IrDA, Bluetooth

ATtiny85

  • GCC Architecture: avr25
  • Program Memory: 8KB
  • TWI: 0
  • SPI: 0
  • USART: 0
  • ADC: 4x10b

ATTINY85-20SU

  • Package: 8-SOIC
  • CPU Frequency: 20MHz
  • $2.24@1, digi-key
  • $1.63@100, digi-key

ATTINY85-20MUR

  • Package: 20-QFN (4x4)
  • CPU Frequency: 20MHz
  • $2.08@1, digi-key
  • $1.51@100, digi-key

ATtiny841

  • Program Memory: 8KB
  • GCC Architecture: avr25
  • CPU Frequency: 16MHz
  • TWI: 1 Slave
  • SPI: 1
  • USART: 2

ATTINY841-SSUR**

  • Package: 14-SOIC
  • $2.11@1, digi-key
  • $1.53@100, digi-key

ATTINY841-MUR*

  • Package: 20-QFN (4x4)
  • $2.16@1, digi-key
  • $1.56@100, digi-key

ATTINY841-MMHR

  • Package: 20-VQFN (3x3)
  • $2.32@1, digi-key
  • $1.68@100, digi-key

ATtiny88

  • Program Memory: 8KB
  • GCC Architecture: avr25
  • CPU Frequency: 12MHz
  • TWI: 1
  • SPI: 1
  • USART: 0

ATTINY88-MU

  • Package: 32-VQFN (5x5)
  • $1.82@1, digi-key
  • $1.32@100, digi-key

ATTINY88-AU

  • Package: 32-TQFP (7x7)
  • $1.96@1, digi-key
  • $1.42@100, digi-key

ATtiny40

  • Program Memory: 4KB
  • GCC Architecture: avrtiny10
  • CPU Frequency: 12MHz
  • TWI: 1 Slave
  • SPI: 1
  • USART: 0

ATTINY40-MMHR

  • Package: 20-VQFN (3x3)
  • $1.49@1, digi-key
  • $1.09@100, digi-key

ATTINY40-XUR

  • Package: 20-TSSOP
  • $2.20@1, digi-key
  • $1.60@100, digi-key

ATTINY40-SUR

  • Package: 20-SOIC
  • $2.14@1, digi-key
  • $1.55@100, digi-key

ATtiny828

  • Program Memory: 8KB
  • GCC Architecture: avr25
  • CPU Frequency: 20MHz
  • TWI: 1 Slave
  • SPI: 1
  • USART: 1

ATTINY828-AUR

  • Package: 32-TQFP (7x7)
  • $2.45@1, digi-key
  • $1.78@100, digi-key

ATTINY828-MUR

  • Package: 32-VQFN (5x5)
  • $2.67@1, digi-key
  • $1.94@100, digi-key

MEMS Microphones

  • I2S digital input type
  • Sensitivity: http://www.analog.com/en/analog-dialogue/articles/understanding-microphone-sensitivity.html -- In near-field applications, such as cell phones, where the microphone is close to the sound source, a microphone with higher sensitivity is more likely to reach the maximum acoustic input, clip, and cause distortion. On the other hand, a higher sensitivity may be desirable in far-field applications, such as conference phones and security cameras, where the sound is attenuated as the distance from the source to the microphone increases. -- Normal Conversation at 1m is around 63dB SPL

SPH0645LM4H-B*

  • Port: Bottom
  • Frequency Range: 20Hz to 20kHz
  • Sensitivity: -26dB ±3dB @ 94dB SPL
  • SNR: 65dB(A)
  • Supply Volgage: 1.62V to 1.8V to 3.6V
  • Supply Current: 0.6mA
  • Precision: 18-bit (6 additional bits are zeros, making 24-bit total)
  • $3.06@1, digi-key
  • $2.29@1, mouser
  • $1.90@100, digi-key
  • $1.51@100, mouser

ICS-43432

INMP441ACEZ-R7

  • Port: Bottom
  • Frequency Range: 60Hz to 15kHz
  • Sensitivity: -26dB ±3dB @ 94dB SPL
  • SNR: 61dB(A)
  • Supply Volgage: 1.62V to 1.8V to 3.6V
  • Supply Current: 1.6mA
  • Precision: 24-bit
  • $4.35@1, digi-key
  • $3.14@100, digi-key

SPU0414HR5H

  • Output Type: Analog
  • Port: Top
  • Frequency Range: 100Hz to 10kHz
  • Sensitivity: -22dB ±3dB @ 94dB SPL
  • SNR: 59dB(A)
  • Supply Volgage: 1.5V to 3.6V
  • Supply Current: 0.22mA
  • $2.01@1, digi-key
  • $1.10@100, digi-key
  • $1.87@1, mouser
  • $1.03@100, mouser

SPW2430HR5H-B

  • Output Type: Analog
  • Port: Top
  • Frequency Range: 100Hz to 10kHz
  • Sensitivity: -42dB ±3dB @ 94dB SPL (not good)
  • SNR: 59dB(A)
  • Supply Volgage: 1.5V to 3.6V
  • Supply Current: 0.11mA
  • $1.11@1, digi-key
  • $0.60@100, digi-key
  • $1.04@1, mouser
  • $0.59@100, mouser

MCU - DFT Audio Signal Processor

  • Interface: I2S

ESP8266*

ATSAMD21

ATSAMD21E18A-MUT

  • Package:32-VFQFN
  • $5.30@1, digi-key
  • $3.88@100, digi-key

ATSAMD21E15B-AUT

  • Package:32-TQFP (7x7)
  • $3.16@1, digi-key
  • $2.32@100, digi-key

IrDA Transciever

IrDA Sensor Pair

IrDA Processor

  • Encoder/Decoder

ATtiny MCU

MCP2155

MCP2122

IrDA Receiver

VS1838B

TSOP38238

TSOP4038

TSOP4838

HS0038B

TSOP58238

TSOP6238TR

TSMP77000TT

  • Distance: 5m
  • Voltage Supply: 2.5V to 5.5V
  • $1.66@1, digi-key
  • $1.21@100, digi-key

IrDA Transmitter

  • Can be controlled with a 555 timer or an MCU

ATtiny MCU

NE555

  • Supply Voltage: Typically 5V operation
  • Max Frequency: 1MHz

TLC555

  • Supply Voltage: 2V-15V
  • Temperature Range: 0C to +70C
  • Package: 8-SOIC
  • Max Frequency: 2.1MHz
  • $0.72@1, digi-key
  • $0.48@100, digi-key

ICM7555

  • Supply Voltage: 2V-18V
  • Drop in replacement for NE555
  • Max Frequency: 1MHz
ICM7555CBAZ
  • Package: 8-SOIC
  • Temperature Range: 0C to +70C
  • $0.73@1, digi-key
  • $0.50@100, digi-key
ICM7555IBAZ
  • Package: 8-SOIC
  • Temperature Range: -25C to +85C
  • $0.73@1, digi-key
  • $0.50@100, digi-key

IMU

  • need to detect sitting vs standing
  • may include accelerometer, gyro, barometer, and perhaps magnetometer; why not

MPU9250

  • DoF:9

Environmental Sensor

BMP280


Bluetooth Module for Beacon

nRF24L01+*

  • Chipset: nRF24L01
  • FCC Certified: No

MDBT40P**

  • Chipset:nrf51822
  • FCC Certified: Yes, SH6MDBT40
Comments

No comments yet. Be the first to ask about this board.

Ask about this board

Sign in to BoardRepo

New here? Signing in creates your account; there is no separate sign-up.