I MADE A CELL PHONE!

Kevin Lynagh !!con 2015

(Don’t tell the FCC kthx)

Motofone F3

Smartphones

Dumbphones

Solution: Build my own

awesome phone

Building a phone:

1. Electronic stuff 2. Software stuff 3. Ind. Design stuff

Electronic stuff

J - L a b F a l l 2 0 0 7

L a b T i c k e t 3 N a t n e :

You have 20 minutes to complete this closed-book lab-ticket. fi'P -

1. Determine an expression for the gain G = of the non-inverting amplifier shownin Fig. 1. The triangles indicate the ground (0 V) level, relative to which Vin and Vout arem e a s u r e d . l/_. !//<

: ( y

K,X

<1 fX

Figure 1: Non-inverting amplifier

2. Derive an expression for the input impedance, Zin = Vinlhn} for circuit shown inFig. 2. (Hint: Use the Golden Rules for operational amplifiers and Kirchoff's laws.)

y t f X

= o

Figure 2: What is the input impedance?

CuurCt̂ ^ < <

^ . M ' ^

y

jd ̂ ' ̂ ̂ ̂ jd>^^ ' [ a m d d

(i/AT

-

J - L a b F a l l 2 0 0 7

L a b T i c k e t 3 N a t n e :

You have 20 minutes to complete this closed-book lab-ticket. fi'P -

1. Determine an expression for the gain G = of the non-inverting amplifier shownin Fig. 1. The triangles indicate the ground (0 V) level, relative to which Vin and Vout arem e a s u r e d . l/_. !//<

: ( y

K,X

<1 fX

Figure 1: Non-inverting amplifier

2. Derive an expression for the input impedance, Zin = Vinlhn} for circuit shown inFig. 2. (Hint: Use the Golden Rules for operational amplifiers and Kirchoff's laws.)

y t f X

= o

Figure 2: What is the input impedance?

CuurCt̂ ^ < <

^ . M ' ^

y

jd ̂ ' ̂ ̂ ̂ jd>^^ ' [ a m d d

(i/AT

-

J - L a b F a l l 2 0 0 7

L a b T i c k e t 3 N a t n e :

You have 20 minutes to complete this closed-book lab-ticket. fi'P -

1. Determine an expression for the gain G = of the non-inverting amplifier shownin Fig. 1. The triangles indicate the ground (0 V) level, relative to which Vin and Vout arem e a s u r e d . l/_. !//<

: ( y

K,X

<1 fX

Figure 1: Non-inverting amplifier

2. Derive an expression for the input impedance, Zin = Vinlhn} for circuit shown inFig. 2. (Hint: Use the Golden Rules for operational amplifiers and Kirchoff's laws.)

y t f X

= o

Figure 2: What is the input impedance?

CuurCt̂ ^ < <

^ . M ' ^

y

jd ̂ ' ̂ ̂ ̂ jd>^^ ' [ a m d d

(i/AT

-

Needed: Cellular computer chip thingy

UMTS/HSDPA Module Series UC15 Hardware Design

UC15_Hardware_Design Confidential / Released 47 / 78

The following figure shows the reference design of the 8-pin USIM card.

Module

USIM_VDD

USIM_GND

USIM_RSTUSIM_CLK

USIM_DATA

USIM_PRESENCE

22R

22R

22R

VDD_EXT

51K

100nF USIM holder

GND

GND

ESDA6V8AV6

33pF 33pF 33pF

VCCRSTCLK IO

VPPGND

GND

USIM_VDD

15K

Figure 30: Reference Circuit of the 8-Pin USIM Card

Some AT commands are invalid when USIM card is not applied.

UC15 supports USIM card hot-plugging via the USIM_PRESENCE pin. For details, refer to document [1] about the command AT+QSIMDET. If you do not need the USIM card detection function, keep USIM_PRESENCE unconnected. The reference circuit for using a 6-pin USIM card holder is illustrated as the following figure.

USIM_CLK 14 DO Clock signal of USIM card.

USIM_RST 15 DO Reset signal of USIM card.

USIM_ PRESENCE

11 DI USIM card detection input. 2.6V power domain

USIM_GND 8 Specified ground for USIM card.

NOTE

Quectel

Confidential

Software stuff

+ detect buttons presses + blink the lights + ask the cellular chip 4 calls + detect low batteries, cellular connectivity, &c.

Tiny computer, big responsibilities

$8

$8

11 MHz

128kB program space!

$8

11 MHz

128kB program space!

$8

11 MHz

1.4 jQuerys!

+ no threads + no garbage collection + no sleep(); + no callbacks

No Operating System

Industrial design stuff

assembly gif

I’m 350 hours in.+ 80h research / sketching / thinking + 70h software + 70h electrical engineering + 30h design / manufacturing + 30h workin’ with my hands

Making stuff is hard.

Celebrate your

victories!!

Thanks!

(secret mailing list)

keminglabs.com/phone/

@lynaghk